Allow user to specify an ad hoc name when submitting ad hoc attendance

Currently, all ad-hocs have their attendance listed under the general "Ad-Hoc" category. This makes sense as is, because we dont want to have to update the database every time there is a new adhoc or if an adhoc is not recreated.

However, it would be cool if, when a user selects the "ad-hoc" option in the attendance dropdown, a textbox appears that lets them type in a label for their attendance.

This would also make it easier for eboard members to figure out what an attendance is on the attendance history page when they are trying to approve it.