Added CSS styling for info and error boxes in manage UI

Also added a convenience "Close all" link that is only shown when more
than 3 boxes are displayed. This link will close all open boxes.

Change-Id: I0ff1806af5db9422e7780fb044497542117ecb82
Fix small token import bug

The 'yubikeycsv' option in the load_tokenfile JS function was declared as
'if' instead of 'else if'. Since the next option was the 'else' condition
(show error), this error message always got displayed.

Reformatted the function to avoid this kind of error in the future.

Change-Id: Ibecc2b1f15abf3836e21159d2a678db1be861808
Merge "Added CSS styling for info and error boxes in manage UI"