* Don't lower Recommends to Suggests on format 1.0
 * Don't allow backslashes in Recommends/Suggests/Depends in format 1.1

Try hard to get lintian error "blends-dev: python-script-but-no-python-dep usr/share/blends-dev/blend-gen-control" solved - no idea why this failed.

The idea is to have a consistent and transparent behaviour between udd
and apt update methods.

Since some time, provides may be versionized. They are handled here by
just ignoring them.