New files for database
*Update for review:
1. Apache license information added
2. docstrings added for config props.

Change-Id: I59b90fec8d9dcba0905e1b20f6b323d0874d275a
Cleanup of server behaviors

* Added eypdoc strings to each method
* Made wait_for methods more consistent with other implementations

Change-Id: I9c9850588d3e084015391347ff97eda7d0ce6765
Porting Tenant API models and configuration

Change-Id: I657ab4c77a279f9f825777d39baad3688c37e396
Refactored image behaviors

* Modified polling methods to match standard CC style
* Added create_active_image function

Change-Id: I20f53550f5738f61d3ffea852e79b824111426a5
Merge "Porting Tenant API models and configuration"