Removed matrixAutoUpdate From Animation 

Removed the lines forcing matrixAutoApdate and matrixWorldNeedsUpdate to true from Animations update and reset. Per Issue #5704
I didn't find that "object.matrixWorldNeedsUpdate = true;" was necessary. I could be wrong, but since setting that to true on every render is basically the same things as having autoupdate set to true they basically do the same thing yes?

 Before the pull request I've removed all lines in my copy and noticed no negative side effects, only the results I expected which were for my objects only to have they're matrices updated when I told them to.

I could be wrong though.