CentralNotice v2.3 DB Schema Updates

Pushing the majority of SQL changes at once so they are available
at code development/deployment time.

Major features being deployed include:
* Mobile integration (carrier, device type selection)
* Ability to archive campaigns and banners
* Partial slot filling (campaign weighting)
* Stacked slots (controller mixins & optional banners)

Change-Id: If91202ff409d6c882f7ae8d47c167552b5d62107
Merge "CentralNotice v2.3 DB Schema Updates"