* If this is a legal user name, assign an integer id to this user name * * What Characters Are Allowed in Twitter Usernames * * Taken from: http://kagan.mactane.org/blog/2009/09/22/what-characters-are-allowed-in-twitter-usernames/ * * A while back, when I was writing Hummingbird, I needed to look for Twitter usernames in various strings. More recently, I’m doing some work that involves Twitter at