Merge tag 'v0.2.1'

This changeset was originally applied to the `0.2.0` release directly
because backwards-incompatable changes have since landed on the `master`
branch.

In addition to resolving the merge conflicts, update the test
environments to load third-party libraries from their location in the
`bower_components/` directory, and use the AMD "shim" config to denote
the global variable exposed by D3.js.

Conflicts:
	.gitignore
	test/index.html
	test/lib/d3.js