Test Plan:
(details on using the tool are at:
https://engineering.redhat.com/trac/rhn-hosted/wiki/EUS/ChannelTaxonomy/Tools)
* Create a channel
* associate a taxonomy data with the channel. Note that the maker, etc must
already exist in the database.
* Ensure that the channel is now categorized correctly in the channels list

Happy to test it, but where does rhn-taxonomy live?  rhncc repo doesn't seem to
have it.

rhn-taxonomy is post 504. this is just for --add-taxonomy.

Test plan:
  Read taxonomy data for a channel -
    rhn-manage-channel-internal --server dev --read-taxonomy
--label=rhel-i386-server-5
  Read taxonomy for a non-existant channel and ensure an error is shown.
  Update taxonomy data for a channel -
    Use the data from a read saved to a file, updating values.
    rhn-manage-channel-internal --server dev --update-taxonomy=my-taxonomy.csv
    Use --commit to save the changes and verify them via read-taxonomy or the webui.
    Alter some values to bad data and ensure appropriate errors are returned.
    Ensure that trimline and releasestate can be empty.
  Add taxonomy data for a channel -
    create a new channel with rhn-manage-channel-internal, then use the
--add-taxonomy=a-taxonomy.csv option to associate taxonomy data with that channel.