fix(dropdown): remove `C` restrictions to avoid conflicts

Fixes #2156

BREAKING CHANGES: Both `dropdown` and `dropdown-toggle` are only attribute directives

Before:
  ```html
  <btutton class="dropdown-toggle" ...>
  ```
  After:
  ```html
  <btutton class="dropdown-toggle" dropdown-toggle ...>
  ```

Closes #2170
feat(datepicker): add open-on-focus option
Merge commit 'b663a7dd77cd95395c957cffe5ca39ff078130ad'
Make the datepicker close automatically after a date is picked, can't write the date manually in the input box right now though
Fix buttons in popovers only working the first time the popover is opened

Code from https://github.com/jbruni/bootstrap-bower-jbruni/blob/master/ui-bootstrap-tpls.js