Improve nice names for cats and horses by including the variant/type.

Reuse actionData.var to store horse variant or cat variant, depending on which entity we're dealing with, instead of having two variables, one of which would end up not being used

Improve nice names for horses.
What used to be "horse" can now be either "horse", "mule", "donkey", "skeleton horse" or "undead horse".

Only use improved nice names if actionData.var isn't null
Merge remote-tracking branch 'origin/master'