Remove pre-compiled bootstrap CSS

Issue #44.
Import Bootstrap Less CSS sources

Imported from bootstrap repo. HEAD at:

    commit 13b96677bacf3de360a762d11ad0e0007f0710da
    Merge: aeee718 0bb122a
    Author: Chris Rebert <github@rebertia.com>
    Date:   Mon Nov 4 11:24:32 2013 -0800

        Merge pull request #11335 from twbs/version-number-updater

        add Grunt task to change version numbers

Issue #44.