Fix problems from merge discussion. Complete Javadoc.

defaultConfig.properties

dummyPrinterConfig.properties

src/main/java/de/tudresden/inf/mci/brailleplot/App.java

...tudresden/inf/mci/brailleplot/ConfigurationValidator.java

.../java/de/tudresden/inf/mci/brailleplot/ValidProperty.java

...resden/inf/mci/brailleplot/configparser/Configurable.java

...inf/mci/brailleplot/configparser/ConfigurationParser.java

...ailleplot/configparser/ConfigurationParsingException.java

...leplot/configparser/ConfigurationValidationException.java

.../mci/brailleplot/configparser/ConfigurationValidator.java

...de/tudresden/inf/mci/brailleplot/configparser/Format.java

...sden/inf/mci/brailleplot/configparser/FormatProperty.java

...eplot/configparser/JavaPropertiesConfigurationParser.java

...ot/configparser/JavaPropertiesConfigurationValidator.java

...e/tudresden/inf/mci/brailleplot/configparser/Printer.java

...den/inf/mci/brailleplot/configparser/PrinterProperty.java

...esden/inf/mci/brailleplot/configparser/ValidProperty.java