Only send terminal state to interacting players

This splits the computer state (blinking, label, etc...) and terminal
state into two separate packets. When a computer changes, the computer
state is sent to all players and the terminal state is sent to players
who are curerntly using the computer.

This reduces network usage by a substantial amount.

src/main/java/dan200/computercraft/client/proxy/ComputerCraftProxyClient.java

@@ -383,6 +383,7 @@ public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
         switch( packet.m_packetType )
         {
             case ComputerCraftPacket.ComputerChanged:
+            case ComputerCraftPacket.ComputerTerminalChanged:
             case ComputerCraftPacket.ComputerDeleted:
             {
                 // Packet from Server to Client
@@ -417,6 +418,7 @@ public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
             // Packets from Server to Client //
             ///////////////////////////////////
             case ComputerCraftPacket.ComputerChanged:
+            case ComputerCraftPacket.ComputerTerminalChanged:
             {
                 int instanceID = packet.m_dataInt[ 0 ];
                 if( !ComputerCraft.clientComputerRegistry.contains( instanceID ) )