Djh fixes

[dhermes]

@craigcitro I wanted to see what you thought about this before moving too far ahead. It is best digested commit-by-commit, rather than as a big diff.

I know (at the very least) I need to add some tests.

[dhermes]

See googleapis/google-cloud-python#335

[craigcitro]

going to look at this now -- but i've gotta clone and look locally, since github can't handle the first commit. ;)

[dhermes]

Oh yes, I should also mention the docs are serving at
http://dhermes.github.io/oauth2client
courtesy of
https://github.com/dhermes/oauth2client/tree/gh-pages

[dhermes]

I just rebased on top of #84 and squashed the hack into a single commit and the test code into a separate single commit.

[dhermes]

After ripping out require_refresh in #84 this is now out of sync, but I am going to hold off doing a fixed rebase until #84 is in.