Repository reorganization

Hello and here are some news...

...and they consist in reorganization of the code repository, so I've cleaned up the mess, removed needless files, especially some math docs.
Also, I've accepted the following branching scheme:
    master as master,
    release for releases tags.
    develop for development process,
    multiple futures branches for futures(thanks, CO!)

Just screenshot

Yope, just a screenshot of morning styling, but lots of works anyway. :)

Good news everyone!..

And the news are really good! OpenSAI is finally painting!
Sure, there're many of bugs, but I think it is the landmark anyway. Because the bugs will be fixed soon.

Some changelog:
* Layers control widget.
* Settings manager window.
* The painting and render pipeline.
* Navigation and preview widget.
* Primary/secondary color widget(works without bugs! Absolutely finished widget)
* Tool's settings.
* Piemenu for the canvas. (Will be more augmentable, for example the possibility to hook any action to the menu)
* OS X compatibility, thanks to John Wells for the pull request!

So, the screenshot in addition.