fix pickability of NoMetaError

fs/errors.py

@@ -61,8 +61,9 @@ class FSError(Exception):
     def __unicode__(self):
         return unicode(self.msg) % self.__dict__
 
-    def __getstate__(self):
-       return self.__dict__.copy()
+    def __reduce__(self):
+        return (self.__class__,(),self.__dict__.copy(),)
+
 
 
 class CreateFailedError(FSError):
@@ -139,6 +140,8 @@ class NoMetaError(FSError):
     def __init__(self, meta_name, msg=None):
         self.meta_name = meta_name
         super(NoMetaError, self).__init__(msg)
+    def __reduce__(self):
+        return (self.__class__,(self.meta_name,),self.__dict__.copy(),)
 
 
 class NoPathURLError(ResourceError):