public/js: Ran closure linter fixjsstyle tool

- Replaced double quoted strings by single quoted string
- Added or removed whitespace where appropriate
- Added or removed semicolons where appropriate
assets: Removed jQuery copy from repository

Load it from the CDN instead if necessary
assets: Updated jQuery to 1.9.1

The $.browser module needs to be included explicitly now. It is deprecated
by the jQuery developers but some of our libraries still depend on it.

The code was copied from:
https://github.com/jquery/jquery-migrate/blob/master/src/core.js