for command of this type "scontrol update reservationname=x users-=x

Fix parsing problem when adding or removeing accounts/users to an existing reservation

preserve a reservation's start_time_prev value

first association record and just use NO_VAL to match the account's 
association record

Set a job's resv_ptr only on slurmctld restart or reconfig, 
  then use xassert() rather than redundant calls to find a 
  reservation by name.

Fix logic for testing if reservations overlap considering DAILY reservation flag

  a node count at the same time.

for reservations

added some tracking of associations in the database.  Primarily used for hourly rollup to determine reserved and over allocated time

log reservation creation/update info
disable logging of incoming reservation RPC contents

	(with no reservation). It previously just permitted use of
	avail_node_bitmap, which didn't work properly immediatedly 
	after startup until nodes registerdd.

since it is needed in all of the same places (the job record now
has a pointer to the reservation structure, which has a pointer
to the partition record). Fix some scheduling logic too.

there is more work yet to do, but it's tricky, so i'm committing what works now

fix logic for checking if reservations overlap (avoid comparison with self)

add logic to authenicate a job's access to a reservation at submit time based upon account and user_id only
(not association)

Still under development
svn m_e_r_g_e -r16224:16292 https://eris.llnl.gov/svn/slurm/branches/slurm-1.4.resv