Implement account elsewhere deletion.

First step towards fixing #639.
Add UI to elsewhere account deletion.
Add tests, fix bug.
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.
Merge branch 'master' into disconnect-639

Conflicts:
	gittip/elsewhere/__init__.py
	gittip/models/_mixin_elsewhere.py
	templates/connected-accounts.html
	tests/test_elsewhere.py
	tests/test_participant.py
style change: use an actual button
Merge branch 'master' into disconnect-639
fix error handling
fix error messages
fix tests
add a failing test
Added heart-coin SVG. [gittip/building.gittip.com#3]
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? :<
Merge branch 'master' into disconnect-639
log account disconnect
Don't show cents on leaderboard after $1000
Add HuBoard badge to README.
Merge pull request #2095 from patcon/add-huboard-badge

Add HuBoard badge to README
DRY up `_to_age` and `format_money`