Fixed Who handler

Updated to manage parameters for filtered searchs (filters by race,
class, zone, name, guild and/or level are now included, by using r-, n-,
g-, c-, z- in your searchs)
Fixed to receive only characters for the same faction (be careful! Low
level pandarens are on their own faction and can't get other char's
info!)
Thanks to Destalker for point me the right behaviour of the searchs :)