Update to use OSLO db

This code implements the blueprint oslo-db-support

NOTES:
1. The new section is database (this is backward compatible
   with DATABASE)
2. The sql_* are deprecated. They are also backward compatible.
3. Eventlets DB pool is no longer supported

Change-Id: I6fa7c3817f6a5d8bef48382e0e754b88521f2289
Merge "Update to use OSLO db"