Merge remote-tracking branch 'drkranz/fixes' into merge

* drkranz/fixes:
  ad348f8d has been superseded by 3daf09a3
  rrd-release-freeze-dates: drop obsolete dates
  rrd-release-freeze-dates: add wheezy release date
  upload.source can be null, fall back to upload.changes
  update-db: display descriptions before deploying update modules
  update-db: automatically find the schema nunmber to upgrade to