implemented priority queue based scheduler
monkey patched queue implementation
using scheduler for cdevs
reschedule childs when dispatching IC
fixed a bug in PQueue#read_while
schedule components at init time
PQueue#delete now returns the deleted element or nil if not found
Merge branch 'master' into scheduler

Conflicts:
	lib/devs/classic/coordinator_impl.rb
pdevs coordinator uses scheduler
Merge branch 'master' into scheduler
pdevs coordinator initialize scheduler at init event
Merge branch 'master' into scheduler
Merge branch 'master' into scheduler
cleanup
removed pqueue dependency
use #reschedule instead of #unschedule / #schedule
* cleanup
+ minimal list scheduler implementation
remove pqueue dependency
wrong require path
fixed bug in binary heap scheduler