WorkerHandle tracks worker load
Reporting thread leak

Because AWS maintains uninterruptable thread pool >:(
Added monitoring thread
Added monitoring sample class
Monitoring samples the head every 1s
WorkerHandle can be set for automatic decommision
Scheduler thread filters out starving workers
Head can starve and decommission a worker
Monitoring thread makes decisions

Lease and release grounded to false
Bugfix
Bugfix
WorkerHandle exposes workload
HeadNode exposes worker pool
Better handling of dead client connections
HeadNode knows when it is waiting for a node
Lease and release conditions
Emulator preloads images
Merge pull request #14 from rvanheest/Monitoring

Monitoring