Small CSS adjustments for compact mode

A couple of fixes:
* Rule to avoid the back link to be underlined when it is rendered as
a button for the compact version of ULS.
* Fix for a 1px misalignment between search box and suggestion (the
1px is needed only when search box has a 1px border)
Merge pull request #81 from pauginer/compact-version-styling

Small CSS adjustments for compact mode