Improved exceptions

Many exceptions got an improvement due to changed class or description or details it is providing.
Is not complete, needs to be done in patches in the regions, where it is needed, since some are just
swallowed.

Removed total usage of pure RuntimeExceptions to 0.

src/main/java/appeng/server/AECommand.java

@@ -27,10 +27,9 @@ import net.minecraft.server.MinecraftServer;
 import com.google.common.base.Joiner;
 
 
-public class AECommand extends CommandBase
+public final class AECommand extends CommandBase
 {
-
-	final MinecraftServer srv;
+	private final MinecraftServer srv;
 
 	public AECommand( MinecraftServer server )
 	{

src/main/java/appeng/server/ServerHelper.java

@@ -58,13 +58,13 @@ public class ServerHelper extends CommonHelper
 	@Override
 	public World getWorld()
 	{
-		throw new RuntimeException( "This is a server..." );
+		throw new UnsupportedOperationException( "This is a server..." );
 	}
 
 	@Override
 	public void bindTileEntitySpecialRenderer( Class tile, AEBaseBlock blk )
 	{
-		throw new RuntimeException( "This is a server..." );
+		throw new UnsupportedOperationException( "This is a server..." );
 	}
 
 	@Override
@@ -179,6 +179,6 @@ public class ServerHelper extends CommonHelper
 	@Override
 	public void missingCoreMod()
 	{
-		throw new RuntimeException( "Unable to Load Core Mod, please verify that AE2 is properly install in the mods folder, with a .jar extension." );
+		throw new IllegalStateException( "Unable to Load Core Mod, please verify that AE2 is properly install in the mods folder, with a .jar extension." );
 	}
 }