Made it easier to switch between dev/prod apps.
Get rid of non-working billing stuff.

All the interesting code for the "My Billing" option is now
in hd-signup. I've gotten rid of everything here, and just
made it redirect to there.
Add all the "My Billing" stuff.
Make some final changes for dev server support.

Now all signup links, including my billing, send you to the dev
signup app. I also fixed the url of the dev signup app.
Make user greeting take up less space.
Merge pull request #12 from djpetti/dash_devel

Fixed Billing