change karma path to pixi build ...

gulp build pixi to bin/pixi.js

Initial Reorganization ...

This commit was the first to start the rewrite of PIXI

1. Removes meta files not necessary to be in the core repo (docs,
examples, random trim/ folder, etc)
2. Rewrite grunt workflow to be gulp
3. Setup testing and browserify tasks to prepare for code rewrite
4. Trim trailing space from the readme