RCUE: Multiselect Component added

Hi Robb,

This is the multi-select component for RCUE using bootstrap-multiselect plugin:
http://davidstutz.github.io/bootstrap-multiselect/

Couple of issues I've noticed:
* This plugin does not work in IE8
* Like other dropdown menus, when the selected items are longer than the dropdown box the text goes behind the caret down arrow icon.

~ JK ~

Commit Squashed Comments:
1. Adding multiselect dependency to bower.json
2. Initial setup multiselect-dropdown HTML, CSS and JS
Setup multiselect HTML; Included
../components/bootstrap/dist/js/bootstrap.min.js. Copied
bootstrap-multiselect.less into working /less folder.
Updated JavaScript initialization to setup multiselect's width,
container CSS and button CSS.
3. Multiselect: move javascript to rcue-util.js and HTML to dropdowns.html