async meta caching: can stream updates now

weed/filesys/meta_cache/meta_cache_init.go

@@ -0,0 +1,10 @@
+package meta_cache
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+)
+
+func InitMetaCache(mc *MetaCache, client filer_pb.FilerClient) error {
+
+	return nil
+}