Add simple timeout example
Fix some bugs and misbevhaviour in custom_optimize()

* The timeout is now cancelled when the optimization is already
  finished.

* Handle the case where the optimization finished without finding any
  paramters.
__name__ for import package
more pythonic value checking
always provision a new worker when releasing one
Merge branch 'Bengt-StatusDB' into develop

Conflicts:
	examples/sleep_gridsearch_global_timeout.py
	metaopt/core/main.py
	metaopt/invoker/multiprocess.py
	metaopt/invoker/util/task_worker_db.py
Merge pull request #11 from cigroup-ol/develop

StatusDB