TINYGL: Maths Code Refactoring

This pull request represents the completion of the first deliverable of my Google Summer of Code project.
The PR contains the c++ style math refactored code.
This code mantains the same level of performance of the original version (even though sometimes it also run  faster).
If you have any questions or doubts please ask.
You should put the empty implementation here, otherwise there probably won't be no overhead, as your comments in the implementation say. (how could the compiler know that the function has an empty body when all it has to work with is the header?)