CLOUDIFY-1536 Extract ping agent health logic from ServiceGridOrchestrator to TaskBasedAgentHealthProbe

Reviewer: Itai Frenkel
CLOUDIFY-1536 Remove optimization of handling agents at undetermined state during initial start of
ServiceGridOrchestrator. Until we have proper test and proper testable solution
CLOUDIFY-1536 Remove nowTimestamp from AgentHealthProbe, the API now returns the health state for all monitored agents.
Merge pull request #1 from CloudifySource/extract_agent_probe

Extract agent probe