Reminders UI Updates

https://trello.com/c/6qVcF5dd/13-clean-up-commconnect-ui

Probably easiest to review commit by commit. The changes in this PR are:
- Allow starting a reminder on a specific day of the week
- Minor formatting changes mentioned in the trello card under "Changes to Date Options"
- Replace use of select2 with typeahead for asynchronous lookups in the ui

![reminder_ui_pr](https://cloud.githubusercontent.com/assets/1028814/4565022/584d1418-4f1c-11e4-9771-3a1fa78e2b29.png)
I would get rid of this line, or keep it consistent with the fields below it.