Solve branch in migration path

Bug #1153578

Also, change a comment line in another migration where the 'revises' line
was incosistent with the id of the actual down_revision

Change-Id: I8effd70ba553330f9023605a2bfa92bd3d73bd4e
Sets default MySql engine to InnoDB

Fixes bug 1153594

Change-Id: I4a3de87a99ca2d49b6a74d7104daf47f8f421a80
Merge "Solve branch in migration path"