Tick generator using provided interval.

Close #1166.
Fix formatting.
Improve jsdoc and include domain boundaries in generated ticks.
Merge branch 'develop' into interval_tick_gen
Fix merge conflict.
Fix jsdoc.
Fix jsdoc.
Extract drawing logic to drawers.

Close #1106.
Move drawing logic to drawers.

Close #1106.
Fix tests and introduce range.
Merge branch 'develop' into interval_tick_gen

Conflicts:
	plottable-dev.d.ts
	plottable.js
Simplify tests and tick generator.
Added Interaction.Hover.

Interaction.Hover acts on any Component that has implemented the
Hoverable interface, which allows the Interaction.Hover to query
the Hoverable for data given a cursor position.

Added a hoverMode() call to AbstractBarPlot, which will allow
Interaction.Hover to replace the Interaction.BarHover.
Add in hoverInteractionTests.ts
Merge branch 'develop' into hover-interaction

Conflicts:
	plottable-dev.d.ts
	plottable.d.ts
Add more tests.
Refactor Interaction.Hover to be clearer.

Factored out the diff-ing of HoverData.

JSDoc-ed Hoverable.
Remove paint method.
Add in missing semicolons.
Merge branch 'develop' into 1106_drawers

Conflicts:
	plottable.js
	src/components/plots/abstractBarPlot.ts