Remove strict sql_mode setting which breaks apps.

Strict sql_mode settings are very application specific, many will simply
not work with them. This setting was likely inherited from some other
production MySQL config file and is not appropriate for a generic
configuration. Specifically, this broke the MySQL package maintainer
scripts.

Change-Id: I068fcc7b3c770541d3d1ecfb372384750f182584
Fix mysql migration script to handle errors.

Errors in mysqldump would have been missed due to not having pipefail
set. Also there was a type-o in the invocation of mysqldump that was
going undetected, that has been repaired. Finally we should not pass
--master-data if we don't have slave credentials, as the master data,
even if provided, is useless without a valid slave user/pass.

Change-Id: I0f80af34c747f465250ef17fae4a44dac919c9cd
Merge "Remove strict sql_mode setting which breaks apps."
Merge "Fix mysql migration script to handle errors."