[Review] Request from 'aduffeck' @ 'SUSE/machinery/review_140915_migrat_to_format_version_2'

Please review the following changes:
  * c0e8d7c Add integration test for "machinery upgrade-format"
  * b74d7a6 Generate pretty JSON when upgrading system descriptions
  * ac854bb Write format migration from version 1 to version 2
  * 49f6be8 Bump format version
  * 26ec833 fix test
  * 524457c Also add extracted flag to unmanaged-files scope
  * b6377ea Store "extracted" state in config- and changed-managed-files scope