Fix repository structure

The following commits re-arrange the entire folder structure to be more "mainstream". This new structure makes viewing code and making changes and pull requests **much** easier. This is the final result:

* https://github.com/FlixelCommunity/Flixel-Power-Tools

Instead, the `Docs` and `Test Suite` can be found in their own branches (with commit history intact):

 * https://github.com/FlixelCommunity/Flixel-Power-Tools/tree/docs
 * https://github.com/FlixelCommunity/Flixel-Power-Tools/tree/test-suite

And for the pièce de résistance, the complete ZIP containing source, docs, and the test suite can instead be found in [the "releases" section](https://github.com/FlixelCommunity/Flixel-Power-Tools/releases):

 * [Flixel Power Tools v1.9 ZIP](https://github.com/FlixelCommunity/Flixel-Power-Tools/releases/download/v1.9/flixel-power-tools-v1.9.zip)

Or if you only want the SWC:

 * [Flixel Power Tools v1.9 SWC](https://github.com/FlixelCommunity/Flixel-Power-Tools/releases/download/v1.9/flixel-power-tools-v1.9.swc)