Fix 500 on invitations new on unknown facebook user... bad solution, maybe we should just delete the offending invitations?

Make resque job specs specific about what error should be raised; fix expectation on hoptoad notifier

Fix errors when trying to mail comment notifications to post authors on posts other than status messages

add hovercards back to mentions, reorganized some helpers, made getting started view mobile accessible

Protect ourselves from problems with youtube title serialization by rescuing type mismatches in the marshaller.