Add total animation duration limit endpoint to control the time for whole iterative delay animation.

Close #1117.
Update jsdoc and currect null check.
Renaming to privide better understanding for knobs' priority.
Fix naming/jsdoc.
Fix jsdoc issues.
Merge branch 'develop' into total_animation_duration

Conflicts:
	plottable-dev.d.ts
	plottable.d.ts
	plottable.js
Merge pull request #1127 from palantir/total_animation_duration

Add total animation duration limit.