[ci] boot.local is gone ... use var/adm/fillup-templates to detect SUSE systems
[api] default to "bnc" bugtracker also for new installations
[webui] re-add missing referenced images.

Fixes failure of new sprockets
[backend] add a "hasbuildenv" flag so that the scheduler goes into "localrebuild" mode
[backend] cleanup patchproductkiwi a bit
[backend] fix buildenv bdep generation

There was a bug that made the bdep names contain the .rpm suffix.
Fortunatelly we can easily workaround this when reading old
buildenv files.