activeDuration tests. Also modified normalization tests to work again.
calculatePhase tests.
calculateActiveTime tests.
calculateScaledActiveTime tests.
calculateIterationTime tests.
calculateCurrentIteration tests.
calculateTransformedTime tests.
AnimationNode tests.
Responded to review comments.
Merge pull request #14 from shans/timingTests

Timing tests.
player
Added reverse() and finish(). Started writing some tests.
Lots of tests, tweaks to algorithms.
Made playbackRate read only
Prevent start time from being set when seeking while paused.
Ignore changes to start time while paused.
Fix finishing behaviour
Review comments.
Merge pull request #18 from shans/player

Player object and methods.
Make source private on Player