first draft junction nodes
still to be done:
* check edge type on junction nodes
* avoid circles in junction chains
* check multiplicities on junction nodes

major refactoring, no more edge ends and auxiliaries
check multiplicity on junctions
check edge type on junction nodes
remove code causing warning
only allow inheritance for edgetypes and nodetypes, not for
junctionnodetypes
beauty, hide junctionNode from external interfaces
Coffebreakjokes: Resources.
remove unnecessary generics
extract interface named
SysML: Stuff
Merge branch 'coffeebreakjokes' of https://github.com/radke-tum/idp into coffeebreakjokes
Merge branch 'coffeebreakjokes' of https://github.com/radke-tum/idp.git into coffeebreakjokes
attributes
remove obsolete code
attributes
* distinguish between MutableNodeTypes and MutableJunctionNodeTypes
* ensure attribute inheritance is working
removed unnecessary generics wildcard
* annotations on element
* use annotations to track edgetypesignature of junction nodes
* getters for nodetypes and junctionnodetypes on metamodel
* PSSIFCanonicMetamodelCreator
* improvements on PSSIFOption create method
towards a compiling transform module