TINYGL: Added a first draft of the maths classes.
TINYGL: Implemented first draft of new matrix and vector classes.
TINYGL: Started replacing the old classes with the new ones.

TINYGL: Removed all the use of the old classes of Vector and Matrix.
TINYGL: Fixed a few mistakes during the refactoring.
TINYGL: Added a few utility methods and operators.
TINYGL: Fixed all the issues that arised after the refactoring.
TINYGL: Fixed an issue with vertices transformation and matrix-vector multiplication.
TINYGL: Fixed a problem with shadows.
TINYGL: Done several optimizations to the maths code.
TINYGL: Done some optimization by moving the logic inside the class Matrix4.
TINYGL: Done some more optimization on maths code.
TINYGL: Last optimization batch, performance comparable to the previous version.
TINYGL: Changed the way vertices are transformed, increased performance (now it's comparable to the previous version and sometimes it performs even faster).
TINYGL: Fixed an error in matrix transpose method and optimized the code a little bit more.
TINYGL: Modified changelog accordingly.
TINYGL: Fixed a regression in maths code.
Merge pull request #916 from subr3v/math-refactoring

TINYGL: Maths Code Refactoring
TINYGL: Moved a few external C functions inside ZBuffer.
TINYGL: Moved all external C functions inside the struct ZBuffer.
TINYGL: Refactored zTriangleFill texture access code.