Random horse coloration added to MobData - "mixed"

[FIlchersSoup]

Added "mixed" to MobData to handle random color and style for horses.

[khobbits]

we already use the phrase 'random' for random colours like sheep, bad idea for a new convention.

[FIlchersSoup]

I assume this means your preference is to incorporate it into the 'random' phrase. The only reason why I created a new convention is random is tightly coupled to the sheep entity in the code, and horses needed both color and style variation.

Let me know. I am sure it can be adjusted to use 'random' and the colorable constant.

[FIlchersSoup]

It looks like the whole horse enumeration part needs to be reworked. I see 23 varieties listed out of 32 and I am not sure all of these would work. I can propose a clean-up of the horse part of the enum and take a look at using the 'random' phrase for horses. If you are not already looking into it, let me know and I will knock it out.

[khobbits]

Feel free, no one is currently working on this code.