The dropdown filter "Category:" contains non-existent options

[ghost]

Zero maps found for all of these categories:

(Release-2015124)
CG420
Co-Op
Conquest (MHQ)
Coop Campaign
FLAMES
Garbage
Husk
King of the Hill
KotH / light tox
Medieval Warfare balance
Medieval Warfare playtest
ModGame
Nexus Wars
No Limits
Original FS Map
Original TS Map
Tox
WHY
tox tox tox tox tox
who cares

It's the same deal with the "Parsed by:" section. These options should be automatically removed when they no longer yield any content.

[pchote]

There is hopefully a way to declare a connection between the Map and MapCategory model such that the categories are automatically deleted when there are no more Map references. If not, we can manually code in a check for each category on a deleted map, and remove any that have 0 uses.