Make python2 explicit in shabang

compiler/2006/Python_CodeGen.jrag

@@ -74,7 +74,7 @@ aspect Python_CodeGen {
 
   public void Program.Python_gen(PrintStream out, String baseName) {
     Python_env env = new Python_env(out);
-    env.println("#!/usr/bin/python");
+    env.println("#!/usr/bin/python2");
     env.println("# Auto generated " + baseName);
     env.println();
     env.println("import labcomm2006");

examples/duck_typing/duck_typing.py

-#!/usr/bin/python
+#!/usr/bin/python2
 
 import labcomm2006
 import animal

examples/simple/example_encoder.py

-#!/usr/bin/python
+#!/usr/bin/python2
 
 import labcomm
 import sys

examples/tcp/example_tcp_client_decoder.py

-#!/usr/bin/python
+#!/usr/bin/python2
 
 import os
 import sys

examples/user_types/example_encoder.py

-#!/usr/bin/python
+#!/usr/bin/python2
 
 import labcomm
 import sys

examples/wiki_example/example_decoder.py

-#!/usr/bin/python
+#!/usr/bin/python2
 
 import labcomm
 import sys

lib/c/version_compare.py

-#!/usr/bin/python
+#!/usr/bin/python2
 
 import os
 import sys

lib/python/labcomm2006/LabComm.py

-#!/usr/bin/python
+#!/usr/bin/python2
 #
 # LabComm2006 packets has the following layout
 #

test/relay_gen_c.py

-#!/usr/bin/python
+#!/usr/bin/python2
 
 import re
 import sys

test/relay_gen_cs.py

-#!/usr/bin/python
+#!/usr/bin/python2
 
 import re
 import sys

test/relay_gen_java.py

-#!/usr/bin/python
+#!/usr/bin/python2
 
 import re
 import sys

test/test_encoder_decoder.py

-#!/usr/bin/python
+#!/usr/bin/python2
 # -*- coding: utf-8 -*-
 
 import argparse

test/test_errors.py

-#!/usr/bin/python
+#!/usr/bin/python2
 
 import sys
 import argparse