go.net/context: update some comments, add a TODO. Use consistent spelling.
go.net/context: update some comments, add a TODO.
Use consistent spelling.

LGTM=bcmills
R=bcmills
CC=golang-codereviews
https://codereview.appspot.com/117170044

ssor/go.net,polydawn-ports/go.net,fernandez14/go.net