Feature/buildsystem

hey there,

to push this project forward i added a buildsystem for it and rewrote everything to LESS. makin it way easier for developers to extend the library or include in parts of it its own projects.

to build everything to spinkit.css (and got a ruby with bundler installed ;-) ) you just need to:

```
cd path/to/SpinKit
bundle install
bundle exec rakep clean && bundle exec rakep build
```

...inside /Assetfile you'll see an commented line which could output a compressed version of the css :-)

cheers,
alex