User theme_username to output user names

Instead of using l(), theme('username', $user) should always be used to output the user name. First, this already provides the check to determine whether or not a link should be used (instead of plain-text), based on the current user's permissions to see profiles. And second, any themes take advantage of this function, which allows them to manipulate them as needed.

Patch attached changes as many occurrences as I could find..

There might be more.