only usecases implemented
usecases updated
comment
imports
comments and imports
control methods
Merge branch 'master'
Conflicts:
	GraphVisualisierung2/src/ch/bfh/bti7301/hs2013/gravis/gui/GuiControl.java
	GraphVisualisierung2/src/ch/bfh/bti7301/hs2013/gravis/gui/GuiModel.java
	GraphVisualisierung2/src/ch/bfh/bti7301/hs2013/gravis/util/ValueTransformer.java