Merge commit 'stew/content_generation' into merge

* commit 'stew/content_generation':
  skip arches we should skip
  i think contents are actually working on separate thread now?
  possibly working multithread contents writer that has udebs disabled
  change reject email template to solicit a reply if new files are uploaded
  convert binaries.type to a enum
  some tweaking to the contents generation queries
  strip ./ from front of paths during contents.bootstrap

Signed-off-by: Joerg Jaspert <joerg@debian.org>