Combine FML's IPlayerTracker and IConnectionHandler into forge events

As 1.7 is nearly upon us it also gives us the opportunity to refactor some packages. I propose to combine FML's network handlers into forge events along with the addition of a ServerListPingEvent. Below I have outlined what I hope to put in my pull request, depending on how much 1.7 changes things. If you think these handlers should remain in FML, I could just convert IPlayerTracker to events and add the extra data shown below along with the ServerListPingEvent.

(Client) net.minecraftforge.client.event.network.ClientConnectionOpenedRemoteEvent

- Was IConnectionHandler.connectionOpened(NetHandler netClientHandler, String server, int port, INetworkManager manager)

- Event would have access to:

  - NetClientHandler, was NetHandler. No longer need to cast to NetClientHandler.

  - Server IP address as string

  - Server Port as integer

  - INetworkManager

(Client) net.minecraftforge.client.event.network.ClientConnectionOpenedIntegratedEvent

- Was IConnectionHandler.connectionOpened(NetHandler netClientHandler, MinecraftServer server, INetworkManager manager)

- Event would have access to:

  - NetClientHandler, was NetHandler. No longer need to cast to NetClientHandler.

  - Server as IntegratedServer, was MinecraftServer. No longer need to cast to IntegratedServer.

  - INetworkManager

(Server) net.minecraftforge.common.event.network.ServerReceiveConnectionEvent

- Was IConnectionHandler.connectionReceived(NetLoginHandler netHandler, INetworkManager manager)

- Cancellable event, a custom kick message could be assigned

- Event would have access to:

  - NetLoginHandler

  - TcpConnection (INetworkManager is an interface of TcpConnection, any reason to not use TcpConnection?)

(Server) net.minecraftforge.common.event.network.PlayerLoginEvent

- Was IConnectionHandler.playerLoggedIn(Player player, NetHandler netHandler, INetworkManager manager)

- Can be combined with IPlayerTracker.onPlayerLogin(EntityPlayer player)

- Event would have access to:

  - EntityPlayerMP

  - NetServerHandler, was NetHandler. No longer need to cast to NetServerHandler.

  - INetworkManager

  - MinecraftServer

(Client) net.minecraftforge.client.event.network.ClientLoginEvent

- Was IConnectionHandler.clientLoggedIn(NetHandler clientHandler, INetworkManager manager, Packet1Login login)

- Event would have access to:

  - NetClientHandler, was NetHandler. No longer need to cast to NetClientHandler.

  - INetworkManager

  - Packet1Login

(Server) net.minecraftforge.common.event.network.PlayerLogoutEvent

- Was IPlayerTracker.onPlayerLogout(EntityPlayer player)

- Event would have access to:

  - NetClientHandler, was NetHandler. No longer need to cast to NetClientHandler.

  - INetworkManager

  - MinecraftServer

(Both) net.minecraftforge.common.event.network.ConnectionClosedEvent

- Was IConnectionHandler.connectionClosed(INetworkManager manager)

- Event would have access to:

  - INetworkManager

(Server) net.minecraftforge.common.event.network.PlayerChangedDimensionEvent

- Was IPlayerTracker.onPlayerChangedDimension(EntityPlayer player)

- Event would have access to:

  - EntityPlayerMP

  - MinecraftServer

  - Teleporter

  - Old dimension id

  - New dimension id

(Server) net.minecraftforge.common.event.network.PlayerRespawnEvent

- Was IPlayerTracker.onPlayerRespawn(EntityPlayer player)

- Event would have access to:

  - EntityPlayerMP

  - MinecraftServer

  - world the player is being respawned into.

  - boolean for if the player beat the game.

(Server) net.minecraftforge.common.event.network.ServerChatRecievedEvent

- Was ServerChatEvent,changed the name to match the client event and move to network package

(Client) net.minecraftforge.client.event.network.ClientChatRecievedEvent

- Move to network package

(Server) net.minecraftforge.common.event.network.ServerListPingEvent

- Event would have access to:

  - Pinger's address

  - Able to send back a custom MOTD

  - Able to send back a custom number of current players

  - Able to send back a custom number of maximum players