Adds material class, ref #139
Replaces PropertyDemo with MaterialObject, ref #140
fixes glm::vec4 for materialobject.
renames materialobject to material and creates core/material folder
tabifies scenehierarchy and materialdemo, ref #140
removes PropertyDemo, adds Widget for Material, ref #140
fixes Material Widget (former PropertyDemo) memory leak, ref #140
hides material tab until needed, ref #140
creates materialmanager, ref #151
makes materialwidget aware of the name of the currently selected polygonaldrawable, ref #152
revisit canvas, ref #154
* detach navigation ownership
* move capture from painter to canvas
* add camera (scene graph entry point) to canvas
* labeled resize issue for ToDo
Fixes selection of scene elements in canvas after refactoring, ref #157
Does something good maybe, ref #157
fixes #157 except the known glm force radians issue
Merge branch 'materials/develop' into materials/master

Conflicts:
	source/core/CMakeLists.txt
	source/core/include/core/navigation/abstractnavigation.h
	source/gui/include/gui/canvas.h
	source/gui/include/gui/viewer.h
	source/gui/source/canvas.cpp
	source/gui/source/viewer.cpp