Dusting the docs

* Fix some typos, grammar, sentence structure
* Fix left-over error tr class
* Remove uneditable inputs section
* Make compatibility sections stand out as sidenotes
* Make modal example scrollable on big screens, too
* Make some examples more self-explanatory
Merge branch '3.0.0-wip' of https://github.com/juthilo/bootstrap-wip into juthilo-3.0.0-wip
add comma; more accurate code snippet
Merge branch '3.0.0-wip' of github.com:twitter/bootstrap into 3.0.0-wip