created FrameBuffer class
Added GLObject base class for all GL objects with methode checkGLError
Mesh and HotMesh are now a GLObject and use checkGLError
Some other objects are GLObject now. Added checkGLWarning (for dtors, ...)
GLObject cannot be copied. More classes derive from GLObject.
Merge branch 'framebuffer' into dev
Renamed Mesh to VertexSeq, HotMesh to HotVertexSeq