Throw away binaries when accepting uploads from NEW

This branch implements options to throw away binaries when accepting sources (uploaded with binaries) from NEW, for certain suites and components. This is intended for unstable (and maybe experimental), and only for main.

Note that this assumes that filenames for buildd uploads contain a suffix, to avoid filename conflicts with the original upload. This currently isn't the case, but this is planned by the buildd admins. This feature should only be enabled once the buildds actually do this.

The removed binaries are moved to morgue. If this is unwanted, the commit that introduces this can just be removed.

This branch contains the changes from !181 (merged), because the added test uses the new data layout introduced there.