fix a number of bugs in d3.d.ts

Most are a result of setter = foo.bar(x), getter = foo.bar()
only reflecting the setter signature.
Merge remote-tracking branch 'upstream/master' into d3-getter-setter

Conflicts:
	d3/d3.d.ts
Merge pull request #2543 from bmalehorn/d3-getter-setter

fix a number of bugs in d3.d.ts