Fix installer downloading vanilla jar when not needed. And filter some more known libraries.

jsons/1.9.4-rel.json

@@ -18,6 +18,7 @@
   "minecraftArguments": "--username ${auth_player_name} --version ${version_name} --gameDir ${game_directory} --assetsDir ${assets_root} --assetIndex ${assets_index_name} --uuid ${auth_uuid} --accessToken ${auth_access_token} --userType ${user_type} --tweakClass net.minecraftforge.fml.common.launcher.FMLTweaker --versionType Forge",
   "mainClass": "net.minecraft.launchwrapper.Launch",
   "inheritsFrom": "1.9.4",
+  "jar": "1.9.4",
   "libraries": [
     {
       "name": "@artifact@",

src/main/java/net/minecraftforge/fml/common/ModClassLoader.java

@@ -131,7 +131,14 @@ public class ModClassLoader extends URLClassLoader
             "log4j-core-",
             "lwjgl-",
             "lwjgl_util-",
-            "twitch-"
+            "twitch-",
+            "jline-",
+            "jna-",
+            "platform-",
+            "oshi-core-",
+            "netty-",
+            "libraryjavasound-",
+            "fastutil-"
         };
         for (String s : prefixes)
         {