Add retry capability to worker processes.
Adjusted a flakey test.
Set default values for retry max and wait times, per Nova admin timeout meeting decision.
Add check for nova server not being ACTIVE status yet.
Removed parameterized decorator as dynamic configuration options are required
Set default retry schedule to 30 seconds, same as for task retries.
Remove retry count from kwargs before key generation; Add more tests of the task key generation
Remove unused heartbeat code.
Merge pull request #725 from jfwood/verify-resource

Add task retry support to Barbican; Also throw exception if Nova status is not ACTIVE on verification;