renamed struct for type of element from FEMElemType to CellType and renamed virtual method getFEMType() to getCellType() in Elemnts class hierarchy

added method AABB::containsAABB() that checks if another AABB object is inside this AABB and added documentation to two other methods

made the declaration of the signature of the copy constructor of class template TemplateHex the same as for imlementation

added (1) FEMElemType to elements as template parameter, (2) method getFEMType() and (3) an enum for FEM element types

Conflicts:
	Gui/DataView/GeoMapper.cpp