FOR REVIEW: Update to jQuery 2.0.1, LESS 1.3.3 and Bootstrap 2.3.1

This pull requests updates jQuery to 2.0.1, LESS to 1.3.3 and Bootstrap to 2.3.1. This is a major update that has several breaking changes.

Major API changes are listed in the [Sprint 26 release notes](https://github.com/adobe/brackets/wiki/Release-Notes:-Sprint-26#api-changes)

Big thanks to @WebsiteDeveloper for the LESS and Bootstrap updates, and @TuckerWhitehouse for the jQuery update.

Remaining tasks:
- [ ] Fix ExtensionManager unit tests (20 failures)
- [ ] Fix FindReplace unit tests (14 failures)
- [ ] Fix Inline Color Editor unit tests (9 failures) (8 fixed, 1 remaining)
- [ ] Fix Url Code Hinting unit tests (2 failures)