Add kick on IP-ban and reason support for IP-bans. Fixes BUKKIT-5371, Adds Bukkit-5384
When the IP of an online player is banned he is not kicked.  Also there is no
ban reason support for the banned IP.  This is a problem because if a
player's IP is banned he will not be disconnected.  Also an admin
cannot give a reason for his/her IP ban (Reasons should be
given for bannng someone).  This commit fixes these issues by adding a 
reason to the BanEntry which is added to the ip-ban list and checking if
there are any online players with the banned IP and kicking them .