Un-skip and fix failing legend tests, fix failing label tests in FF.

Close #137.
put selection box in front\n close #486
fixed tests
Hotfix for #519.

This addresses the issue, by adding a flag to Utils.Text.writeText
to allow the user to force vertical or horizontal writing (leaving
the flag unset keeps the original behavior of guessing the correct
orientation).

CategoryAxis currently forces horizontal text orientation.
Fix #524, crudely, by removing all tickLabels on each render.
Clean up code and remove some extra nested "g"s while at it.
Add unit test to catch this issue in the future.
Update quicktest.
Update built files.
Merge pull request #516 from palantir/fix-unit-tests

Un-skip and fix failing legend tests, fix failing label tests in FF.
Merge pull request #525 from palantir/fix-cat-axis

Fix #524, crudely, by removing all tickLabels on each render.
Merge branch 'master' into HEAD

Conflicts:
	plottable.js
	src/components/categoryAxis.ts
Merge pull request #521 from palantir/519-axis-shift

Hotfix for #519.
Release version 0.15.2
moved opacity to plottable.css file
Merge pull request #520 from palantir/486-hidden

put selection box in front
Add initial version of tak's issues chart
Remove the lineRenderer and second axis
Use CSS for coloring in tak-examples
Include bower.json in the bower release
add Y Drag Box interaction too
Merge pull request #530 from njwhite/feature/YDragBox

add Y Drag Box interaction too
modified interactive legend quicktest
Merge branch 'master' into hover-legend