MBSE for MagicDraw Code

Added support for Slots containing LiteralStrings in GenericTables.

Add provisions for three different types of execution of the xsltFOPExecutor
a) call by method (working with FOP 1.0)
b) call by external system call which spawns another JVM (not completed, CLASSPATH modification still pending)
c) execution of method after modifying the classpath by using a specific Classloader.

direct call (a) is currently enabled, since FOP 1.0 is still in use.

Converted HTML to DocBook in generic table cells.

Removed unnecessary import statements.

proper Utilities class used.

Fixed bug in cleanUpString4FileName.
Forced opening of GenericTable before generation (DiagramPresentationElement.open()), since FOP does not yet like
tables with no rows (and closed GenericTables do not contain any row).

Initial support for RTF. Work in Progress.

Adapted to 18.0 and the introduction of com.nomagic.magicdraw.properties.ElementProperty.

introduced sanitizeFOP(): FOP does not like <itemlist> when there is no <listitem> as can happen with HTML documentation for model elements.

Added MaintenanceActivity and related dependencies.