Restore original meaning of "current"

And make getAnimationPlayers simply return the union of current and in
effect animations. The previous attempt to rework the meaning of current
didn't really make sense.

Generated from:

commit 1610b516acb11471c79772f4297f5db353aa618d
Author: Brian Birtles <birtles@gmail.com>
Date:   Mon Sep 29 14:10:49 2014 +0900

    Restore original meaning of "current"

    And make getAnimationPlayers simply return the union of current and in
    effect animations. The previous attempt to rework the meaning of current
    didn't really make sense.