added check if nodes belong to any elements; reworked legacy mesh input to use getline command so that linux coding will hopefully be no longer a problem

fixed bug in MshEditDialog and added proper error management; removed openmp-loop in mesh class because of race condition

added memory usage output

added rapidxml method for reading vtu files; fixed problem in Mesh::setNeighborInformationForElements - EDGE elements don't have neighbors anymore because they also dont have faces

Conflicts:
	FileIO/MeshIO/GMSHInterface.cpp
	FileIO/MeshIO/GMSHInterface.h
	MeshLib/Elements/Edge.h
	MeshLib/Elements/Element.cpp
	MeshLib/Elements/Element.h
	MeshLib/Elements/Hex.cpp
	MeshLib/Elements/Prism.cpp
	MeshLib/Elements/Pyramid.cpp
	MeshLib/Elements/Quad.cpp
	MeshLib/Elements/Quad.h
	MeshLib/Elements/Tet.cpp
	MeshLib/Elements/Tri.cpp
	MeshLib/Elements/Tri.h
	MeshLib/Node.h