Add python3-compat boilerplate to all .py files in lib/ansible

lib/ansible/utils/module_docs.py

@@ -17,6 +17,10 @@
 # along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
 #
 
+# Make coding more python3-ish
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
 import os
 import sys
 import ast