Make OS-FEDERATION core.Driver methods abstract

Not all methods in contrib.federation.core.Driver are decorated
with @abs.abstractmethod. This patch adds missing decorators.

Change-Id: I93962110134d4b9062a75c228760333403a4f7eb
Correct the region table to be InnoDB and UTF8

The region table was not specified as being InnoDB or UTF8 under
mysql initially. The migration will fail if the defaults for MySQL
are not set correctly. A new method has been added to the
migration_helpers module to detect and correct the InnoDB / UTF8
specific issue with the region table.

Change-Id: I374c3dd46a4292e8f9e74ef75a8bb463b951f135
Closes-Bug: #1334779
Merge "Correct the region table to be InnoDB and UTF8"
Merge "Make OS-FEDERATION core.Driver methods abstract"