Changed the API of Camera.

- The zoom name has been replaced by radius and traveling (indeed this
never was a zoom).
- The very badly named uniformMVP method becomes uniform (it binds all
matrices).
- setUnifomrMVP becomes uniformMVP (it binds only MVP).
- setUniformMV becomes uniformMV
- setUniformMV3x3 becomes uniformMV3x3
- all rotateModel, translateModel, scaleModel, transformModle become
rotate, translate, scale and transform. Since they are used everywhere
this is more practical.
- Added a flag that avoids to recompute the MVP each time uniform or
uniformMVP is called.