fix initial state listen. include 'previous_value' prop on 'replace' operations.

Author: endel

colyseus/state_listener/compare.lua

@@ -53,7 +53,8 @@ local function generate(mirror, obj, patches, path)
           table.insert(patches, {
             operation = "replace",
             path = concat(path, key),
-            value = new_val
+            value = new_val,
+            previous_value = old_val
           })
         end
 

colyseus/state_listener/state_container.lua

@@ -49,8 +49,8 @@ end
 
 function StateContainer:set (new_state)
   local patches = compare(self.state, new_state)
-  self:check_patches(patches, self._listeners, self.defaultListener)
   self.state = new_state
+  self:check_patches(patches, self._listeners, self.defaultListener)
   return patches
 end