python: Create new vlog module.

Currently, each python daemon has to come up with it's own logging
solution.  These logging strategies are not consistent across the
python code or with the C vlog module.  This patch adds a new
logging module which hopes to solve the problem.  This new module
generates log messages in a manner consistent with the C code.
Furthermore, it can easily be extended to support things like rate
limiters in the future.

This patch does not update any python code to use the new module.