CSS tweaks for tags, search, and other small things

Changes made: 
+Gave tags square corners, made them smaller, and slightly opaque.
+Made tags left justified with text above and below. 
+The topbar is back to its original height 
+Old: The "share" url box no longer obscures the controls along its lower edge.
+The space between different facets in the search bar is now a touch tighter.  
+Put highlight and lock icon on same line as username.

You can check out a live demo of the changes here:
http://csstweaks.dokku.hypothes.is