Default result backend should be "amqp"

Also, fix the broken blank postcard generator.
Add  feature
Add Affiliations feature
Add Favorites feature
Hide toggle favorites links when not authenticated
Clear timeout on new affiliation key
Add comment removal notices and mailing types
Merge corrected affiliation timeout
Fix bugs with comment removal form
Add comment unremoval template
Correct url indentation
Update notifications to use new comment removal urls
Require latest django security update
Fix bug with excluding words from search
Add tests for user search
Tighten up requirements
Add travis-ci configuration
Add venv to gitignore
Fix install script targets
Re-organize travis.yml