EMI: Rename PoolChore to EMIChore, move to emi/costume
EMI: Fix actor animations

The current code for loading EMI costumes contains a special treatment that
expects the skeleton and mesh components in a chore named "wear_default".
This assumption is not valid for costumes that contains multiple wear chores,
most notably for Guybrush who has a different outfit for each island.

The new code considers any chore containing skeleton and mesh components
to be a wear chore. The skeleton from the last played wear chore will be
animated.
GRIM: precise lua header about modifications
Merge pull request #779 from inguin/emi-actor-anim

EMI: Fix actor animations