Allow schema upgrades to display messages

It's possible that the execution of a SQL statement is not critical to
the success of a schema upgrade. An example of this is a function that
during the upgrade gets removed from the database. It is possible that
this function may have been removed by the user manually, and the fact
that it is already missing should not block the upgrade from
proceeding.

Bug: 500
Change-Id: Ie9aa0d732f884a6d749d864ee3a43d257af272b7
9 files changed