Fixes chetan51/nupic.cerebro2#2. Added play/pause and speed scrubber.
Speed up drawing
Removed pause button - replaced with method for switching text in the play button.
Refactored based on feedback. Also removed unnecessary pause button disabling, since that button has been removed.
Merge pull request #8 from jefffohl/issue2

Fixes chetan51/nupic.cerebro2#2
Showing both 3D and 2D visualization on the same page, and keeping them in sync
Refactored code and hiding controllers on children visualizations