Enhancement crystals: Allow downslotting!

[rahubby]

I think that enhancement crystals should be able to be placed in any slot that is it's slot size OR BIGGER. So an item with a Large slot should be able to slot a tiny, small, medium OR large crystal, instead of just a large one. The reason I think this would be good is, in a lot of small guilds, it will be a LONG time before you can use a large crystal, and meanwhile you might have dozens of pieces of gear you'd like to be able to slot, but their guild crystal slots would be completely useless to you.

Also, if crystals are going to be limited by what item they can go in, let us filter by item in the merchant. If we only have a hat slot, we shouldn't have to spend time looking at all the crystals we don't have slots for.