cf #1497 - added some kind of 'trust' rule, not accepting flags from new users
cf #1497 - added a rule to delete flags if the user is not trusted
passing tests, removed a print
cf #1497 - now send emails anyway + tests cases
comment cleanup
doc + cleanup
Reworked the code to be more generic, added a specific email for untrusted user warning
desactivated a few non sense tests (which could fail if the mail templates were overrided)
improved emails and tests
the trust evaluation function is now easily overridable + a test for it.
Merge pull request #9 from lauxley/master

added a rule to not take into account flags from 'untrusted' users