EMI: Fixed interpolation between animations and cleaned up the related code.
EMI: Implement keys for the animation component.

Key 3 seems to control whether the animation loops or not. If key 3 is not
set, the animation plays once and then deactivates. If the key is set, the
animation will repeat until the chore is stopped.
EMI: Allow StopChore without fade time parameter.
GRIM: Fix typo in GrimPatchesDesc.txt
Merge pull request #846 from Akz-/emi-anim-fixes

EMI: Animation fixes
GRIM: Fix the pause in Manny's walk backwards animation. Fixes #137
GRIM: Clean up the MeshFace code
GRIM: Make copyMeshFace an assignment operator
GRIM: Make data in MeshFace private
GRIM: Instead of using a assignment operator, just steal the data

This avoids potential memory leaks.