Move from Python logging to Openstack logging

Replacing usage of python standard logging module
with Openstack common logging module. Apart from
the said replacements, this patch also removes
basicConfig() setup from a couple of modules since
its not needed. Also removes unused LOG & imports.

Change-Id: I6a391951e00fb63905b2027270af9f401841d5b9
Closes-Bug: #1350937
Simple refactor to stop passing around an unused parameter

There is no functional change in this patch.  However, this refactor
allows another patch [1] to make a simpler change to the code base.

This patch includes localizing the initialization of "internal_cidrs"
to a later spot in the "process_router" method.  This has the
advantage that it will be initialized under the same condition that it
will be used.

[1] https://review.openstack.org/#/c/109776

Change-Id: I3ca993d0a33b7c925526099e97999c9d9f76efc2
Merge "Simple refactor to stop passing around an unused parameter"
Merge "Move from Python logging to Openstack logging"