Adds a leading semicolon

Safely concatenating with other js files :)
<http://stackoverflow.com/questions/1873983/what-does-the-leading-semicolon-in-javascript-libraries-do>
Added Gitter badge
Merge branch 'gitter-badger-gitter-badge' into develop
Moved the gitter badge inline.
Merge branch 'fritx-patch-1' into develop
Improved readme

Moved URLs to the bottom and cleaned up the testing section. Also
improved the contribution section some more by making it more prevalent
and highlighting which branch pull requests should be pointed at again.