Expand to include weekend meetings

[BenShelton]

Dependant on #58 first.

If we can store a talk list then we can use the existing list of brothers to assign to. However we'd need a free form entry for visiting brothers which breaks the paradigm we had before. Maybe a toggle between local and visiting brothers, one uses the dropdown but the other is free form?

Whatever the case we'd need some refactoring to separate concerns for a lot of these components. Some are more tightly bound to the talk structure, or maybe we design a whole new week component for weekend meetings. Plus we'd have to store new data on each week too, and find some nicer way to display it.