* Improved notifications management in MX checks.
see #1820
* Increased alarm internal code length.
* Force greenlet 0.4.16 due to a binary issue with 0.4.17.
* Improved coverage.
- add support for looking up IPv6 addresses (socket.getaddrinfo)
- add support for International Domain Names in case the DNS reponse contains one, to_unicode() decodes them to a utf8 string
- add logging for potential configuration errors:
- DNS configuration errors (i.e. no MX records)
- server name resolution errors (i.e. resolv.conf doesn't contain a working name server)
- invalid values in MX records
- when looking up an ip address, don't stop on the first failure check all addresses
- update mock results for tests, return a real MX record for mock dns queries
* Check MX validity when adding new domain.
see #1211
* Fixed unit test.
see #1215
* Added unit tests.
see #1211
* Fixed unit test.
see #1211
* Added missing file.
see #1211
* Fixed error definition.
see #1211
Antoine Nguyen