IMC tweaks: runtimeMessages now work (thanks for all that testing for this much requested feature!)

and IMCEvent will no longer remove messages if no one gets them, so you can do
just manual runtime polling, if you wish.

fml/common/cpw/mods/fml/common/event/FMLInterModComms.java

@@ -44,17 +44,23 @@ public class FMLInterModComms {
      *
      */
     public static class IMCEvent extends FMLEvent {
+        private ModContainer activeContainer;
+
         @Override
         public void applyModContainer(ModContainer activeContainer)
         {
-            currentList = ImmutableList.copyOf(modMessages.removeAll(activeContainer.getModId()));
-            FMLLog.finest("Attempting to deliver %d IMC messages to mod %s", currentList.size(), activeContainer.getModId());
+            this.activeContainer = activeContainer;
+            FMLLog.finest("Attempting to deliver %d IMC messages to mod %s", modMessages.get(activeContainer.getModId()).size(), activeContainer.getModId());
         }
 
         private ImmutableList<IMCMessage> currentList;
 
         public ImmutableList<IMCMessage> getMessages()
         {
+            if (currentList == null)
+            {
+                currentList = ImmutableList.copyOf(modMessages.removeAll(activeContainer.getModId()));
+            }
             return currentList;
         }
     }
@@ -202,7 +208,7 @@ public class FMLInterModComms {
         ModContainer mc = FMLCommonHandler.instance().findContainerFor(forMod);
         if (mc != null)
         {
-            return ImmutableList.copyOf(modMessages.removeAll(mc));
+            return ImmutableList.copyOf(modMessages.removeAll(mc.getModId()));
         }
         else
         {