Set build update log level to debug

We get this a lot.  It's not helpful.

Change-Id: Icf0191ded019c705a42446269d647cb52843ef58
Reviewed-on: https://review.openstack.org/36733
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Monty Taylor <mordred@inaugust.com>
Approved: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins
Use integer comparison for patchsets

When checking for a new version of a change, compare patchsets
as integers.

Change-Id: Ic5ceae9e89cd28a9f391896bcdbf68313d70adc4
Reviewed-on: https://review.openstack.org/36734
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Monty Taylor <mordred@inaugust.com>
Approved: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins