Description of problem: Within katello we want to allow users to use usernames of email addresses. For this to work properly in katello pulp needs to support this as well. I'm sure there is an RFC somewhere but good ole' wikipedia says these characters need to be allowed: !#$%&'*+-/=?^_`{|}~ for the username. @ and '.' also need to be allowed. http://en.wikipedia.org/wiki/E-mail_address#Valid_email_addresses
This was originally requested for use with katello/headpin but is (or soon will be) unnecessary. Instead of using the same user name from katello/headpin, a sanitized version will be passed to pulp. Leaving the status as NEW; leaving it up to pulp folks to decide if it's necessary for non-katello environments.
It's actually non-trivial due to a restriction in mongo. If this isn't needed for Katello, I'm closing this out since the work involved is reasonably extensive.