Cleanup: PEP8 fixes
When searching, filter should point to 'All'
When going away from a search, ensure we clean up values

Having text in the search box and a filter other than 'All' might result
confusing otherwise, because we don't support filtering search results
just yet.
Point to the proper URL pattern

Thanks to Leandro Regueiro for spotting this.
Cleanup: don't load unused template tag
Aligned sorting control styling
Also select everything when clicking on unit indexes
Avoid excessive bottom padding
Moved action bar CSS into its own file
Fixed vertical alignment