Basic Scheduling

Last large issue (I think). Basically, store an RSet on the database, and keep a log of when door events happen. Don't do event caching yet until we can do some benchmarks. https://github.com/rlanvin/php-rrule

We are going to have two types of schedules that a group can have. First off is the door schedule for when they go into open mode, second is the group users schedule for when those users are allowed in the door.