Cleanup: removed dead code
Cleanup: removed oldIE-specific code
Avoid weird layout when no option is selected
Respect the asynchronous nature

The value retrieved from the query arguments was being overwritten and
therefore the select option wasn't being properly set.
Properly hide checks when switching to search
Enabled unit sorting for all filters

Sorting is enabled based on unit's last modified time, with the exception
of the filters that already implement a context-aware sorting.

Since this affects unit navigation, the sorting control has been moved
next to the previous/next/goto controls. This still needs some styling
love though.

Fixes #102.
Cleanup: simplified code