Refactored for BS3 compatibility

Added events. Added new backdrop. Removed touchstart listeners.
Fixed backdrop click
Update Dropdown.js
Update Dropdown.js
Update Dropdown.js
Update Dropdown.js
Update Dropdown.js
Update Dropdown.js
Update Dropdown.js
Update Dropdown.js
Update Dropdown.js
Update Dropdown.js
Update Dropdown.js
Update Dropdown.js
Update Dropdown.js
Fixes #107. Use correct selector for finding actives