Added (in)equality operator(s) to Color
Texture3D tests
Added an invalid state excepion
A lot of changes to Texture3D
(lost git history due to corruption so I'm recommiting)

* Getters for the texture dimensions
* Getter for the Texture3D data
* Constructor for empty texture3D
* Bind/Unbind now const
* An obnoxious getter for texture id
* A bit of refactoring and renaming
Shader uniform can now set a vec3 of floats
No need for graphics common (we rely on the library to initialize itself)
VolumeData::SetVoxel now takes a const color reference,
also factored out the destruction
Draw only one object
Removed a lot of hacks and turned them into proper code
Added a few more for testing purposes (but I'm working on it)
Normal map generator, hardware and software normal map generation
still now perfect (work in progress)
Shader code is now in text files
White spaces
Added and removed files