BarPlot now draws labels after animations have finished (if there are any) or immediately (if not)
For example, see negative_stacked_bar quicktest.
No longer special-case synchronous rendering when time=0.
Instead, make a mocked version of setTimeout for better testing.
Thanks to Andrzej for this suggestion.
Merge pull request #1237 from palantir/labels-on-bar-timed

[DoNotMerge] BarPlot now draws labels after animations have finished