* remove unused mBufferMappings
    * warn when mapping multiple locations to same attachment
    * cap size for bufferMappings at GL_MAX_DRAW_BUFFERS
    * bind FBO before validate()

- VertexBuffer and FrameBuffer renamed to VertexBufferObject and FrameBufferObject respectively. This convention is more consistent regarding the State, which now gets a FrameBufferObject (FBO), VertexBufferObject (VBO) and ShaderProgramObject (SPO)
- Added controllers and objects to the Controller.hh and Objects.hh respectively
- Added corresponding managers

Validation methods have been added VertexBuffer::validate() and FrameBuffer::validate().
These are called by State::validate()

Added the class State to the framework in order to manage combinations of VertexBuffer, FrameBuffer and ShaderProgram.
The class automatically creates a mapping between the attributes of vertexbuffers and shaders.
Furthermore a mapping between FragDatas of shaders and rendertargets of framebuffers are created.

Removed static contexts from the opengl object. In future, this has to be handled by our opengl wrapper, which will hold a copy of the gl state on cpu side.
Made all opengl contexts not copyable.
Created a macro for the shared typedefs which directly creates a const version of the pointer.
Started to change some opengl object functions to be non-const although they might not change any class members, because the function still might change something on gpu side. Therfore, returning the context of any opengl object is also non-const now!
Changed the renderbuffer constructor to just create the context and moved the rest to its corresponding controller.
Removed own type enums in opengl objects => ONLY use the orginial GLenums here!

Until now only the class Texture used it. Now it has been added to ElementArrayBuffer, ArrayBuffer, FrameBuffer and ShaderProgram.
Static class members have to be initialized outside the header, so the file ElementArrayBuffer.cc had to be added.
Unbind calls e.g. glBindBuffer(GL_ARRAY_BUFFER, 0) outside of the specific class are not useful anymore, because it
would not reset the static context variable and thus lead to bugs/crashes.

* Added additional OpenGL error checks
* OpenGL error checks are better usable with namespaces
* Removed checks for OpenGL objects == 0 which would get ignored by OpenGL anyway and are rare
* Added comments
* improved OpenGL ES compatibility