go/doc: s/typeDoc/typeInfo/
go/doc: s/typeDoc/typeInfo/

To avoid confusion between typeDoc and TypeDoc.
No semantic change.

R=r
CC=golang-dev
http://codereview.appspot.com/5502071
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go