Fix Meeting.get_by_date

With this new query, the function retrieves all the meetings that either start or stop in
the time frame considered

Relates to https://fedorahosted.org/fedocal/ticket/61
Filter out part of meeting which do not belong to the week

This change remove from the list of meetings to display all the part of meetings that
either start earlier or end later than the week considered.
This is necessary for full day meeting starting on a Sunday.

Fixes https://fedorahosted.org/fedocal/ticket/61
Make the FakeUser part of 2 groups and having signed the CLA
Small formatting change
More formatting changes
When retrieving the meetings of a week, expand the recursive meetings directly

This way recursive meetings are directly accessible in the list of meetings present in a
week.
Fix unit-test, sometime tests give a single group instead of a list of groups
Little code cleaning and improve documentation
Move Meeting.expand_regular_meetings into Week.get_meetings and Week.get_full_day_meetings
Merge pull request #30 from fedora-infra/fix_full_day_sunday

Fix full day sunday