Replaced all instances of `#!/usr/bin/python` with `#!/usr/bin/env python` so impacket's examples and scripts can be run inside a virtualenv without having to call python.
Now there should be a single logger called 'impacket' the library uses.
By default is has a NullHandler so nothing is printed, but messages are
forwarded to the upstream logger.
If you are a script using the library and want to set the root logger
with a custom formatter, you can import impacket.examples.logger.
After some testing I'll merge it into master
Martin Gallo