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.
Merge pull request #846 from Akz-/emi-anim-fixes

EMI: Animation fixes