Add layout config object to model

Store the results of the configuration (pipelines, jobs, and all)
in a new Layout object.  Return such an object from the parseConfig
method in the scheduler.  This is a first step to reloading the
configuration on the fly -- it supports holding multiple
configurations in memory at once.

Change-Id: Ide56cddecbdbecdc4ed77b917d0b9bb24b1753d5
Reviewed-on: https://review.openstack.org/35323
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins
Perform live reconfiguration

Change-Id: I69563ee47dd6f3777a52b67999ff1a03247f1e1e
Reviewed-on: https://review.openstack.org/35324
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins
Add TESTING file

Change-Id: Ifa3ff45189b794dfb2c29e127599dbe547b57f71
Reviewed-on: https://review.openstack.org/35354
Reviewed-by: Anita Kuno <anteaya@anteaya.info>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins