Use env python

Change the shebang from /usr/bin/python to /usr/bin/env python
Some users, especially on older systems don't use the python
supplied with the OS. This has an impact with module loading if
the python in /usr/bin is 2.6, and user wants to use 2.7
in /usr/local/bin, for example

Change-Id: Ib31b369a94c33fb7508f0539c2b2f14177e507e0
Merge "Use env python"