samba/logger: add logger module for python

samba/logger: add logger module for python

We need a consitent way for logging in Samba Python code.

This module provides a factory method `get_samba_logger` to create logger,
with a reasonable default format and optional color.

Signed-off-by: Joe Guo <joeg@catalyst.net.nz>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>