Porting of Scheduler (WIP)

Scheduler code from github.com/vladimirvivien/gomes and other fixes.  
*  Port of exising gomes code
*  Changed code to match @yifan-gu existing infrastructure
*  Additional code toward completion of all handlers
*  Added tons of tests, but more to be added later
*  Also includes a scheduler example in examples/sched

Also here - do you want to leave the commented code in?