updated d3.d.ts, but broke everything

Incremental bugfixes we put into d3.d.ts are blown away.
I'm going to fix them, but I should have this checkpoint.
corrected a bunch of bugs in d3.d.ts

Now compiling. Will submit PR to DefinitelyTyped soon.
Merge pull request #729 from palantir/update-d3-definitions

Update d3 definitions