Made TestClient descend from SecondLife.
Exposed the list of Avatars in AvatarManager, because I thought it was doing the same thing as TestClient.Avatars. I'm no not so convinced of this and will probably revert the changes tomorrow.
Added EchoMaster command as an example of a bot that responds to chat messages.
git-svn-id: http://libopenmetaverse.googlecode.com/svn/trunk@728 52acb1d6-8a22-11de-b505-999d5b087335
