Moved the apidocs from openstack/database-api

By hosting the docs here we'll be able to better maintain that
developers are being mindful of changes or even occassionally writing
documentation for new API features. This should also allow us to
autogenerate the snippets.

Change-Id: I0111bcd38341b1736a47b0a3d3e6ff96d2ca1c58
Corrected the assert message in test_dbaas.py

Change-Id: Id0a6a9b3b674bfe724bcb83764a628388cfd38f6
Closes-Bug: #1311621
Updated from global requirements

Change-Id: Iab7b6ed1890b7da98f4916dc90b523b52674f59c
Merge "Corrected the assert message in test_dbaas.py"
Merge "Moved the apidocs from openstack/database-api"
Merge "Updated from global requirements"
Adds the foundation for datastore capabilities

This allows for capabilities to be set in the mysql database capabilities
table and associated to datastores with the datastore_capabilities
table. This allows users to have datastore specific functionality that
is configurable and able to be served to end users. This commit is for
the groundwork for the capabilities API.

Change-Id: I7153d435bf8c00dc2a874a66c7a2b64e8fbafa09
Partially-Implements: blueprint capabilities