Limit user searches for proprietary code to users in the Team

When adding users to one of our private git repositories on Bitbucket, the text completion offers users from the entire BitBucket user name space, not just our company's users.

Members of our company's team are identified with a "TEAM MEMBER" icon, but it is very easy to accidentally add an external user to a repository if names are similar.

The security ramifications of exposing our company's (and everyone else's!) proprietary code in this way are obvious.

This is a serious user interface bug and needs to be fixed.