Switch to OpenGL 3.2 core profile (needed for MacOS support)
Use correct shader version 150 for core 3.2
implement ogl 3.2 core rendering
* fix deinitialization
* remove isHandle functions in GPUQuery
* reenable render buffers (supported in 3.2)
* add hack check for core profile
* return true for extension checks in core profile (instead of false)
* add vertex array object for rendering in screen quad
fix #18 enable depth test in polygonaldrawable
Merge branch 'ogl_3_2_core_basis_14' of https://github.com/cgcostume/cgsee into ogl_3_2_core_basis_14

Conflicts:
	apps/cgsee/painter.cpp
fix #17
* fix shader versions specifics and switch to core
* disable qpainter for overlay painting due to unsupported 3.2. core
* move paint to paintGL and discard paintEvent since we require swap
fix #17
* always try to force swap interval if qt does not work
* remove extension check for swap interval
* add dummy impl for apple - left todo
fix #16
* add empty __APPLE__ double check
* change Fatal to Warning log
ref #14 remove tabs and trim some lines
ref #14 undo personalization
fix #17
* implement better context double check dummy for os x
Fix GL_INVALID_OPERATION when VAO is deleted twice when calling PolygonalDrawable::deleteBuffers
fix #20
* check objio
* add per face normal retrieval in geometry for now
Fix GL_INVALID_OPERATION and other GL errors when GL functions are called with OpenGL context already removed

Objects shall be destroyed in inverse order.
Update AUTHORS
Merge pull request #22 from cgcostume/objio_enhancement_20

fix #20
Merge branch 'master' into ogl_3_2_core_basis_14

Conflicts:
	apps/cgsee/cgsee.cpp
	configure
	libs/core/polygonaldrawable.cpp
Merge branch 'master' of https://github.com/cgcostume/cgsee into ogl_3_2_core_basis_14

Conflicts:
	apps/cgsee/painter.cpp
	libs/core/polygonaldrawable.cpp
Merge pull request #24 from cgcostume/ogl_3_2_core_basis_14

Ogl 3 2 core basis 14
Fix OpenGL warnings on MacOS