Makes auto-reversal of transitions work more completely and correctly, fixing some API issues and other related animation/effect issues along the way. Seeking behavior in effects is improved (although still far from perfect, especially for non-playing effects), and dynamic behavior of effects (picking up values dynamically from the environment) is improved.
QE Notes: better seek() behavior, can just call it on non-playing effects and it will automatically play/pause the effect if necessary
Doc Notes: None
Bugs: sdk-17294, sdk-16595, sdk-18104, sdk-18105, sdk-18106, sdk-18107
tests: checkintests, Mustella: tests/Effects, tests/gumbo/effects tests/ListDataEffects