Swap charts from gRaphael to D3

Summary:
Mostly, this has just been sitting in my sandbox for a long time. I may also touch some charting stuff with subprojects/milestones, but don't have particular plans to do that.

D3 seems a bit more flexible, and it's easier to push more of the style logic into CSS so you can fix my design atrocities. gRaphael also hasn't been updated in ~3+ years.

Test Plan:
{F1085433}

{F1085434}

Reviewers: chad

Reviewed By: chad

Subscribers: cburroughs, yelirekim

Differential Revision: https://secure.phabricator.com/D15155