Reorder the Connected Accounts in markup

This still isn't a user-facing change yet, but the next one should be.
This sets us up to group and restyle the Connected Accounts. Follow-on
from #2122, moves us towards #2053.
drop the website.aaaaaaand_venmo variable
remove some comments of questionable usefulness
Merge pull request #2123 from gittip/reorder-accounts

reorder accounts in markup