Add notes to the "Record an Exchange" admin

The semantics of amount and fee are ... interesting. Until that's
cleaned up properly, here is a little bit of help for those of us who
have to use this form.
add a failing test
move aspen options from command line to env file
fix linkify when no protocol is provided

why doesn't Python let you assign variables in lambdas? :<
Don't show cents on leaderboard after $1000
DRY up `_to_age` and `format_money`
Merge branch 'master' into ui/leaderboards/format-large-amounts-of-money
Use VCR fixtures on branches in Travis

It's good to exercise live HTTP APIs, and Travis is the place to do
that, but it slows down development to do that on every branch all the
time. This commit changes our configuration to only clear out test
fixtures on the master branch.
Failing test for delete_elsewhere.
Fix failing test.
Fix yaml parsing.
reclean the code
Merge pull request #2106 from gittip/fix-delete-elsewhere

Fix delete elsewhere
Bump version to 12.1.1
Bump version to 12.1.1-dev
Merge pull request #2107 from gittip/travis-network

Use VCR fixtures on branches in Travis
Merge remote-tracking branch 'origin/master' into ui/leaderboards/format-large-amounts-of-money
Bump version to 12.1.2
Bump version to 12.1.2-dev
break `linkify` regex out onto multiple lines