Introduce waiter mechanism

[istraka]

Introduce a way to tell Sunstone to wait for a condition indicating a resource is up.

Proposed requirements:

• Option to identify a resource (@AzureVirtualMachine)
• Option to set a timeout
• Option to set a waiter (provided by Sunstone)
  • HTTP waiter (accepts path & port (optional) )
  • HTTPS waiter (accepts path & port (optional) )
• Option to select 1-N phases where the waiter is applied (after cloud deployment, after WAR deployment, ... )
• I can set multiple waiters in the test class
• Waiter is set in a declarative way using annotations.