Added info on lx## and smurf## build to README.

Revised job API descriptions per feedback.

doc/txt/job.api.txt

-Let's see if we are all on the same page if we use data structures for job APIs.
 The user defines a structure job_desc as below. He then calls slurm_job_desc_init(), 
-which sets the values to initial values (#dead, #deadbeef, or NULL for the pointers). 
+which sets the values to initial values (#ffff, #ffffffff, or NULL for the pointers). 
 The user then set any values as desired, likely only a small subset of the values. 
-Some of the values can be set only by user root (e.g. priority, user_id, group_id). 
+Some of the values can be set only by user root (e.g. groups, priority, and user_id). 
 For example, we ignore the request from user "tewk" to run as user "root" with 
-group id "root" and high priority. The user then calls the appropriate API (allocate, 
+group "root" and high priority. The user then calls the appropriate API (allocate, 
 submit, update, will_run). The API call packs the values reset by the user, including 
 proper values for user_id and group_id. Only the values set by the user are sent, 
-packing in <job_tag><value> pairs. Alternately, we ship all fields in a pre-defined 
-order and forgo the tags. There probably will be little difference in size and 
-it just seems easier to have a fixed order - one just constructs matching pack 
-and unpack functions as we already have in several places. 
+packing a uit32_t value first with flags indicating which values are being sent 
+(see  "#define JOB_DESC_OPT_CONTIGUOUS" and below). The functions return an error 
+code as defined below (see "#define SLURM_SUCCESS" and below). slurm_allocate and 
+slurm_submit functions will return a job_id upon success. 
 
-Is this everyone's understanding? Comments?
-
-stucture job_desc {	/* Job descriptor for submit, allocate, and update requests */
-	uint16_t contiguous;	/* 1 if job requires contiguous nodes, 0 otherwise */
-	char *features;		/* comma separated list of required features */
-	char *groups;		/* comma separated list of group IDs, 
-				 * can only be set if user is root */
-	uint32_t job_id;	/* job ID */
-	char *name;		/* name of the job */
-	void *key;		/* root key to submit job, format TBD */
-	uint32_t min_procs;	/* minimum processors required per node */
-	uint32_t min_memory;	/* minimum real memory required per node */
-	uint32_t min_tmp_disk;	/* minimum temporary disk required per node */
-	char *partition;	/* name of requested partition */
-	uint32_t priority;	/* relative priority of the job, 
-				 * can only be set if user is root */
-	char *req_nodes;	/* comma separated list of required nodes */
-	char *job_script;	/* pathname of required script */
-	uint16_t shared;	/* 1 if job can share nodes with other jobs */
-	uint32_t time_limit;	/* maximum run time in minutes */
-	uint32_t num_procs;	/* number of processors required by job */
-	uint32_t num_nodes;	/* number of nodes required by job */
-	uint32_t user_id;	/* set only if different from current UID, 
+structure job_desc {	/* Job descriptor for submit, allocate, and update requests */
+	uint16_t contiguous;	/* 1 if job requires contiguous nodes, 0 otherwise, 
+				 * default=0 */
+	char *features;		/* comma separated list of required features, default NONE */
+	char *groups;		/* comma separated list of groups the user can access, 
+				 * default set output of "/usr/bin/groups" by API, 
 				 * can only be set if user is root */
+	uint32_t job_id;	/* job ID, default set by SLURM */
+	char *name;		/* name of the job, default "" */
+	void *partition_key;	/* root key to submit job, format TBD, default NONE */
+	uint32_t min_procs;	/* minimum processors required per node, default=0 */
+	uint32_t min_memory;	/* minimum real memory required per node, default=0 */
+	uint32_t min_tmp_disk;	/* minimum temporary disk required per node, default=0 */
+	char *partition;	/* name of requested partition, default in SLURM config */
+	uint32_t priority;	/* relative priority of the job, default set by SLURM, 
+				 * can only be explicitly set if user is root, maximum
+				 * value is #fffffffe */
+	char *req_nodes;	/* comma separated list of required nodes, default NONE */
+	char *job_script;	/* pathname of required script, default NONE */
+	uint16_t shared;	/* 1 if job can share nodes with other jobs, 0 otherwise,
+				 * default in SLURM configuration */
+	uint32_t time_limit;	/* maximum run time in minutes, default is partition 
+				 * limit as defined in SLURM configuration, maximum
+				 * value is #fffffffe */
+	uint32_t num_procs;	/* number of processors required by job, default=0 */
+	uint32_t num_nodes;	/* number of nodes required by job, default=0 */
+	uint32_t user_id;	/* set only if different from current UID, default set 
+				 * to UID by API, can only be set if user is root */
 };
 
-int slurm_job_desc_init (stucture job_desc *job_info);
-int slurm_allocate (stucture job_desc *job_info);
-int slurm_job_update (stucture job_desc *job_info);
-int slurm_submit (stucture job_desc *job_info);
-int slurm_will_run (stucture job_desc *job_info);
+int slurm_job_desc_init (structure job_desc *job_info);
+int slurm_allocate (structure job_desc *job_info, uint32_t *job_id);
+int slurm_job_cancel (uint32_t job_id);		/* user_id passed by API */
+int slurm_job_update (structure job_desc *job_info);
+int slurm_submit (structure job_desc *job_info, uint32_t *job_id);
+int slurm_will_run (structure job_desc *job_info);
 
-enum job_tag { 		/* Used for allocate, job create, or update */
-	CONTIGUOUS,	/* Node allocation to be contiguous, 1=yes, 2=no, uint16_t */
-	FEATURES,	/* Required node features, comma separated, char* */
-	GROUPS,		/* list of user's groups, comma separated, char* */
-	JOB_ID,  	/* Job's ID, uint32_t */
-	JOB_NAME,	/* Job's name, char * */
-	PART_KEY,	/* Key required for partition access, type? */
-	MIN_PROCS,	/* Minimum processor count per node, uint32_t */
-	MIN_REAL_MEM,	/* Minimum MB real memory per node, uint32_t */
-	MIN_TMP_DISK,	/* Minimum MB temporary disk per node, uint32_t */
-	PARTITION,	/* Name of requested partition, char* */
-	PRIORITY,	/* Job's priority, uint32_t */
-	REQ_NODES,	/* List of required nodes, comma separated, char* */
-	SCRIPT,  	/* Pathname of script to execute for job, char* */
-	SHARED, 	/* Nodes to be shared, 1=yes, 2=no, uint16_t */
-	TIME_LIMIT,	/* Job time limit in minutes, uint32_t */
-	TOTAL_NODES,	/* Minimum count of nodes required by the job, uint32_t */
-	TOTAL_PROCS,	/* Minimum count of processors required by the job, uint32_t */
-	USER_ID 	/* User's ID, uint32_t */
-};
-/* Remove Distribution, ProcsPerTask, they go with a job step only */
+/* The following flags indicated which of the job_desc structure entries were set by
+ * the user and packed into the communications data structure. These flags are set 
+ * in an uint32_t variable in the communications data structure and followed by 
+ * those values in order. */
+#define JOB_DESC_OPT_CONTIGUOUS		1<<0
+#define JOB_DESC_OPT_FEATURES		1<<1
+#define JOB_DESC_OPT_GROUPS		1<<2
+#define JOB_DESC_OPT_JOB_ID		1<<3
+#define JOB_DESC_OPT_JOB_NAME		1<<4
+#define JOB_DESC_OPT_PART_KEY		1<<5
+#define JOB_DESC_OPT_MIN_PROCS		1<<6
+#define JOB_DESC_OPT_MIN_REAL_MEM	1<<7
+#define JOB_DESC_OPT_MIN_TMP_DISK	1<<8
+#define JOB_DESC_OPT_PARTITION		1<<9
+#define JOB_DESC_OPT_PRIORITY		1<<10
+#define JOB_DESC_OPT_REQ_NODES		1<<11
+#define JOB_DESC_OPT_SCRIPT		1<<12
+#define JOB_DESC_OPT_SHARED		1<<13
+#define JOB_DESC_OPT_TIME_LIMIT		1<<14
+#define JOB_DESC_OPT_TOTAL_NODES	1<<15
+#define JOB_DESC_OPT_TOTAL_PROCS	1<<16
+#define JOB_DESC_OPT_SHARED		1<<17
+#define JOB_DESC_OPT_USER_ID		1<<18
+/* Removed Distribution and ProcsPerTask, they go with a job step only */
 
+#define SLURM_SUCCESS		0	/* API call successfully completed */
+#define SLURM_NOCHANGE		1	/* Data requested unchanged since last get call */
+#define SLURM_EAGAIN		2	/* Try again later (eg. no nodes for allocate) */
+#define SLURM_EACCESS		3	/* Permission denied */
+#define SLURM_EINVAL		4	/* Invalid arguments (eg. can never satisfy request) */
+#define SLURM_ENOENT		5	/* No such entry (eg. cancel with bad job_id) */