[backend] rework dbgsplit code, make packtrack available to plugins

- packtrack needs to be mixed
- deleterepo needs the repoinfo for subdir
[backend] modernize publisher to use store/retrieve from BSUtil
[backend] small code cleanups
report patchinforef in packtrack data

also report supportstatus for testing purposes
[api] fix migration numbering
[api] add initial binary tracking code
[api] add operation flag to binary tracking
[backend] enable binary package tracking for maintenance_release projects by default
[backend] enable tracking when project kind="maintenance_release"
[api] follow binary releases inside of DB
[api][webui] raise code "quality" limit to 80

80 means the function still fits on a standard screen, splitting functions into
more do not make the code more readble IMHO
[build] reference new version for binary parsing
[testsuite] add DISTURL to fixtures rpm
[api] drop build_repository from binary_releases
[test] follow changed srcmd5
[api] order binary release search results by release time
[api] store also patchinfo packager in database
[api] fix cache handling for binary_release
[api] tune maintainer handling
[backend] disallow also product flavor for now

this is not the media flavor.
The better way to maintain extra list of repos is to preinstall an addon product
by default