Have compare-source-package-list extract DEP-3 headers for derivatives-specific patches
compare-source-package-list script source code and rationale can
be found on https://wiki.debian.org/Derivatives/Integration#Patches.
As discussed on the debian-derivatives mailing-list, it would be useful
compare-source-package-list could look into
derivatives-specific patches, and retrieve information from
DEP-3 headers. The Forwarded
field, in particular, would be useful to identify patches that haven’t
been forwarded to Debian (or upstream), but should be.
Parent Task: #7607