domainer.include() added, used on bar plots
old baseline is removed from domainer.include()
got rid of BarPlot._defaultBaseline
this.baseline(this._baselineValue)

back to the old way of resetting domainer + baseline
more clear scale.domainer() jsdoc
style
domainer tests for dates, include(n, false)
Merge pull request #575 from palantir/domainer-include

domainer.include() added, used on bar plots