Description of problem:
It would be useful if the channel.software.listAllPackages XMLRPC call would also expose the package's md5sum (aside from NEVRA and last_modified).

This would help identify potential packages with the different content, but same NEVRA, in two different channels.

When NEVRAs were guaranteed to be unique within an org_id (I believe there used to be a unique constraint on name_id, evr_id, package_arch_id, org_id on rhnPackage), you could get away with comparing the org_id of the channels.

Without this, one would have to iterate over each package and individually fetch the rest of the info, and it's too expensive.