[initial commit] StackedBarPlots are now a thing.
They descend newStylePlot, which implements the new dataset api.
clustered bars
Remove vestigial code
- Stacked extent management handled by _updateAllProjectors
- Add the baseDrawer class
added legend to quicktest (buggy)
Bring axis stylings more in-line with Design's stylings.
752 - Formatters are now simple functions

Close #752.
Merge branch 'master' of github.com:palantir/plottable into 752-simpleFormatters

Conflicts:
	plottable.d.ts
	src/components/numericAxis.ts
	src/utils/formatters/customFormatter.ts
NewStyleBarPlot is now a thing
Merge branch 'stacked-bars-simpler' into clustered-bars
Merge branch 'master' into clustered-bars
remove stacked-bars from this branch
Clean up handling of updateYDomainer, updateXDomainer
clustered bars descend from newstyleplots
Various improvments:
NewStylePlot - interface DatasetDrawerKey so key is easy to obtain and we have just 1 object encapsulating necessary info
StackedBarPlot - now use a keysInStackedOrder array to maintain stacking order
Plot - projectors now store attribute as well as scale/accessor for convenience later
remove shift button
Move the KeysInOrder down to NewStylePlot
onlyShowUnchanged param and dependency fixing
onlyShowUnchanged param and dependency fixing
Merge branch '752-simpleFormatters' of github.com:palantir/plottable into 752-simpleFormatters

Conflicts:
	plottable.js
	test/tests.js
	test/utils/formattersTests.ts