Added External Library figure
Merge branch 'develop' into feature_ExternalLibraries
Changed datamodel by Twan recommendations
Merge branch 'develop' into feature_ExternalLibraries

Conflicts:
	src/husacct/graphics/task/AnalysedController.java
	src/husacct/graphics/task/DefinedController.java
Created method which takes ExternalSystemDTO[] and shownFigures, checks if any of the figures have a dependency with one of the extSystems.
Added checkbox in dialog options for Show External System(doesn't work yet)
merge feature_ExternalSystems, conflicts resolved