Try and handle removal of mods a bit better. Currently no way to allow a world which has missing

blocks to load - but i have the code in place to allow it i think.

src/main/java/cpw/mods/fml/server/FMLServerHandler.java

@@ -23,6 +23,7 @@ import cpw.mods.fml.common.FMLCommonHandler;
 import cpw.mods.fml.common.IFMLSidedHandler;
 import cpw.mods.fml.common.Loader;
 import cpw.mods.fml.common.ModContainer;
+import cpw.mods.fml.common.event.FMLMissingMappingsEvent;
 import cpw.mods.fml.common.eventhandler.EventBus;
 import cpw.mods.fml.common.network.FMLNetworkEvent;
 import cpw.mods.fml.common.registry.LanguageRegistry;
@@ -179,4 +180,9 @@ public class FMLServerHandler implements IFMLSidedHandler
     {
         bus.post(new FMLNetworkEvent.CustomPacketRegistrationEvent<NetHandlerPlayServer>(manager, channelSet, channel, side, NetHandlerPlayServer.class));
     }
+    @Override
+    public FMLMissingMappingsEvent.Action getDefaultMissingAction()
+    {
+        return FMLMissingMappingsEvent.Action.valueOf(System.getProperty("fml.missingBlockAction", "FAIL"));
+    }
 }