Unicycle 2: Bicycle

I wanted to wait for The War Within's pre-patch to settle down a bit before pushing this, just to avoid anything potentially game-breaking in a hotfix I'd then have to leap on. I've also future-proofed this as best I can, so it should be good for a while.

• Change: Dragon-riding is now sky-riding.
• Change: Addition of 'Special' mount list, just for having certain mounts show in your filtered selection.
• Change: Detection for Dragon Isles zones, dragon-related things, and level 60 removed. They're no longer needed.
• Change: The dynamic (was dragon-riding) and flight mount lists are now used according to what flight state you have (vis-a-vis skyriding and dynamic).
• Change: The dragon-riding keybind was removed, now it's just flying or ground/swimming. The reason for this is that it's no longer required, as selecting between skyriding/steady flight is handled by a skill in-game (I'd say that swapping flight states is beyond Unicycle2's purview). So, back to being a bicycle!
• Change: Some under-the-hood refactoring to make all this work as described.