New: Add case-insensitive compare function
Optimize: command parser does case-insensitive comparison
Added isLoggedIn function to locate a currently-logged in user with the given username
New: /mute command adds users to mute list or displays mute list
New: isLoggedIn function gives a pointer to currently logged in user with that name
New: isIgnoringUser function indicates whehter a user is ignoring another user