Add a small arithmetic test to stop spammers

Nothing crazy, but should be fine for now.
Default to 0 when getting bad_answers from session

Typo before, oops. Needs to be set so that it can be deleted afterwards.
Merge pull request #120 from editorsnotes/nospam

Add a small arithmetic test to stop spammers
Change server email
Use emdash entities.
Merge pull request #121 from editorsnotes/emdash

Use emdash entities.
Fail spam test if answer is not a number
Merge pull request #124 from editorsnotes/nospam

Fix spam form
Merge pull request #126 from editorsnotes/all-custom-admin

All custom admin
Merge branch 'master' into improved-setup

Conflicts:
	editorsnotes/settings.py