Bootstrap 3 - Authentication fixes

When only one external strategy is enabled, the "Sign in" links, takes
you straight to the API endpoint.

A couple of small visual fixes are included such as:
 * aligning search icon with "Sign in"
 * proper padding in the sign in drop down
 * dotted border when in small view mode
 * new visual buttons for external strategies

As the external authentication buttons their designs have changed, the
auth-buttons.css file is no longer necessary so it has been removed.

Fixes for #3406 and 3446
Aligned search icon with sign in button
Not showing login popover when the only enabled strategies are cas or shib.
Made the auth buttons for cas and shib skinnable
Merge remote-tracking branch 'simong/bootstrap3-authentication' into bootstrap3-authentication
Follow up on authentication fixes
Merge origin/bootstrap3 and fix conflicts
Merge branch 'bootstrap3' of https://github.com/sakaiproject/3akai-ux into bootstrap3-authentication
Authentication improvements
Move product video out of the modal into the index page
Merge branch 'bootstrap3-authentication' of https://github.com/bp323/3akai-ux into bootstrap3-authentication
Merge branch 'bootstrap3' of https://github.com/oaeproject/3akai-ux into issue-3628
(Issue 3640) Fix vertical alignment inconsistencies in list item buttons
Follow up on productvideo review
(Issue 3641) vertically center deleted message when it extends beyond a single line
(Issue 3642) Use 'hide' class to toggle badge visibility to avoid writing invalid display value
Follow up on authentication issues
Fixed IE9 background-color issue
Merge branch 'bootstrap3' of https://github.com/oaeproject/3akai-ux into bootstrap3
Merge branch 'bootstrap3-issue3641' of github.com:sathomas/3akai-ux into bootstrap3-issue3641
Follow up on deleted comment message