fix interpreter hashbang, fix missing returncode in over.core.cmd

core/cmd.py

@@ -1,4 +1,4 @@
-#! /bin/env python3
+#! /usr/bin/env python3
 # encoding: utf-8
 
 import queue
@@ -66,6 +66,7 @@ class Command:
 		self.__dict__['thread'] = None
 		self.__dict__['fifo'] = None
 		self.__dict__['terminated'] = False
+		self.__dict__['returncode'] = None
 	
 	def dump(self, sequence=None, pretty=False):
 		out = []