Remove url.conf.defaults deprecation warns from Django 1.5 upgrade

Change the names of the url.conf imports to be compatible with Django
1.5 syntax.

Resolves https://github.com/openhatch/oh-mainline/issues/1366
Added subscription form for the news letter
Added monthly news letter link, moved read more link
Correct filter setting for mail-admin for Django 1.4+
Skip time-related test if we are running via MySQL

Closes #1341

The thing about this commit is that MySQL itself supports microsecond precision
just fine. But the Django ORM does not support that through MySQL.

Luckily, we still run this test when we operate with sqlite, so it is reasonably
reasonable to skip it in the case that we are in MySQL mode.
Cleaned up pep8 errors, fixed some deprecated syntax in test files