* move mMode fom ArrayBuffer to VAO
* add attachAllAttributes method to VAO
* allow adding VAO attributes without binding them (location == -1)
* store state of previous VAO binding in static field

* Added constness to the buffers which are hold by the vertex buffer object (otherwise you cannot attach const buffers and there is no reason why this should not be possible)
* IMPORTANT: Fixed a major bug in the ACGL RenderObject which caused a wrong mapping to the array buffers! All projects should update to this newest version of ACGL!

* Fixed warnings in the NURBSCurve class and added an error message when a curve is defined with a missmatching knot vector

* Furthermore introduced a factory to register new file types (currently jpg and png).
* Added support for cube mapping

This commit closes #106, #107

Changed primitive int types in the texture to the correct OpenGL types and fixed the initialization list of the jpg controller

* ShaderProgramControlFiles is similar to ShaderProgramControlAutoFiles but the files
  have to be named explicitly which makes it possible to share some shaders for different
  ShaderPrograms.
* Both ShaderProgram controllers share some code, this should get reduced by refactoring.
* ShaderProgramControlAutoFiles had a copy&paste bug

* now also updates orientation after updating local coordinate system
  (prevents ControlCamera snapping back to old pitch/yaw after manually
  setting the camera position)

Removed the Interfaces.hh and modified the AnimationEvent class to either
call function pointers or member function pointers using class templates.

[Animations] Changed data structure from vector->list
[Animations] Added function to stop a running Animation

* Added a sampling function to the nurbs that also allows for the calculation of the derivatives