Revert "update: bootstrap 2.0.4 -> 2.3.2"

There are minor layout breaks with this patch. Reverting until
we can test it better.

This reverts commit 5e97817de9d8884c25595dfbf6637efedc269862.
Move bootstrap-responsive.css to /external/
Path fixes in /themes/

I'm reapplying fixes that we reverted in the
bootstrap update patch