initial pass at drpm publishing support
some presto delta metadata to use for unit tests
unit tests for drpm metadata
added call to _publish_drpms
publish drpms unit tests
fixed metadata generation that relies on unit_key lookups instead of metadata lookups
metadata fixes based on running unit tests
bug fixes for _publish_drpms resulting from running unit tests
Merge pull request #379 from pulp/jconnor-publish-drpms

Jconnor publish drpms