Merged qutorial zplusplus master.
Fixed model check errors.
Fixed completion of ClassDeclaration template parameters.
Added PlantUML concept documentation generator.
Documentation generator supports model structures with cyclic references.
Cleaned up some unneeded nodes.
Merge branch 'master' of https://github.com/qutorial/zplusplus

Conflicts:
	ZPlusPlus/languages/com.mbeddr.cpp/languages/com.mbeddr.cpp.classes/languageModels/intentions.mps
	ZPlusPlus/languages/com.mbeddr.cpp/solutions/test.ex.cpp.overloading/models/test/ex/cpp/overloading/operators.mps
Merge branch 'master' of https://github.com/qutorial/zplusplus
Merge branch 'master' of https://github.com/qutorial/zplusplus

Conflicts:
	ZPlusPlus/languages/com.mbeddr.cpp/languages/com.mbeddr.cpp.classes/languageModels/constraints.mps
Removed meta model documentation facility
Fixed typo: originial -> original.
Fixed editor: added missing constness flag to editor.
Implemented more complex use case in example.
Before deleting concept restricted parameter type
More debugged C++ is making programs work