Created by: hgezim
Added events for bootstrap-dropdown, namely open, close, opened, and closed. Wrote documentation as well as unit testing.
Ran unit tests and other limited testing on:
Mac: Chrome 23; FF 16, 17; Safari 6 Windows: Chrome 23; FF 16, 17; IE 9
Please merge my changes from feature/dropdown-effects into 2.2.2-wip.