Even more proxy pruning

- Move the "world directory" getter out of the proxy - we can just use
   Forge's code here.
 - Remove the server proxies, as both were empty. We don't tend to
   register any dedicated-server specific code, so I think we can leave
   them out.

src/main/java/dan200/computercraft/shared/peripheral/modem/wired/WiredModemLocalPeripheral.java

@@ -19,7 +19,6 @@ import net.minecraftforge.common.util.Constants;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import java.io.File;
 import java.util.Collections;
 import java.util.Map;
 
@@ -66,10 +65,7 @@ public final class WiredModemLocalPeripheral
             else if( id < 0 || !type.equals( this.type ) )
             {
                 this.type = type;
-                this.id = IDAssigner.getNextIDFromFile( new File(
-                    ComputerCraft.getWorldDir( world ),
-                    "computer/lastid_" + type + ".txt"
-                ) );
+                this.id = IDAssigner.getNextIDFromFile( "computer/lastid_" + type + ".txt" );
             }
 
             return oldPeripheral == null || !oldPeripheral.equals( peripheral );

src/main/java/dan200/computercraft/shared/proxy/CCTurtleProxyCommon.java

@@ -11,7 +11,7 @@ import dan200.computercraft.shared.turtle.core.TurtlePlayer;
 import net.minecraft.util.ResourceLocation;
 import net.minecraftforge.fml.common.registry.EntityRegistry;
 
-public abstract class CCTurtleProxyCommon implements ICCTurtleProxy
+public class CCTurtleProxyCommon implements ICCTurtleProxy
 {
     @Override
     public void preInit()

src/main/java/dan200/computercraft/shared/proxy/ComputerCraftProxyCommon.java

@@ -63,7 +63,7 @@ import net.minecraftforge.fml.relauncher.Side;
 import net.minecraftforge.fml.relauncher.SideOnly;
 import pl.asie.charset.ModCharset;
 
-public abstract class ComputerCraftProxyCommon implements IComputerCraftProxy
+public class ComputerCraftProxyCommon implements IComputerCraftProxy
 {
     @Override
     public void preInit()

src/main/java/dan200/computercraft/shared/proxy/IComputerCraftProxy.java

@@ -10,9 +10,6 @@ import dan200.computercraft.shared.command.text.TableBuilder;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.util.SoundEvent;
 import net.minecraft.util.math.BlockPos;
-import net.minecraft.world.World;
-
-import java.io.File;
 
 public interface IComputerCraftProxy
 {
@@ -22,8 +19,6 @@ public interface IComputerCraftProxy
 
     void initServer( MinecraftServer server );
 
-    File getWorldDir( World world );
-
     default void playRecordClient( BlockPos pos, SoundEvent record, String info )
     {
     }

src/main/java/dan200/computercraft/shared/util/IDAssigner.java

@@ -17,6 +17,16 @@ public class IDAssigner
     {
     }
 
+    public static int getNextIDFromDirectory( String path )
+    {
+        return getNextIDFromDirectory( new File( ComputerCraft.getWorldDir(), path ) );
+    }
+
+    public static int getNextIDFromFile( String path )
+    {
+        return getNextIDFromFile( new File( ComputerCraft.getWorldDir(), path ) );
+    }
+
     public static int getNextIDFromDirectory( File dir )
     {
         return getNextID( dir, true );