Add support for matrix decompose and compose

[sanjayc77]

Based on CSS3 transform spec:

http://www.w3.org/TR/css3-transforms/#decomposing-a-3d-matrix
It also describes decomposing 2d matrix.

While we are at it, maybe support composing matrices given its component parts (translation, rotation, skew, perspective, etc).

Chromium also has an implementation in C++:
https://github.com/ChromiumWebApps/chromium/blob/master/ui/gfx/transform_util.cc

[stefnotch]

These function have been implemented.

[gonnavis]

@stefnotch Hello, thank you very much for your work!

I saw decompose have been implemented, but compose not yet?

[stefnotch]

@gonnavis See https://glmatrix.net/docs/module-mat4.html#.fromRotationTranslationScale and other matrix functions. To compose them, you multiply them.

The only thing that I think isn't in there is skew. There was a pull request to add it a while back, but nothing happened since then. I suppose skewing is a quite rare operation.

[gonnavis]

Thanks a lot!