Logging module cleanup
Logging module cleanup

Replaced logging with openstack.common.log
Removed imports where logging is not used

Fixes bug #1095541

Change-Id: I5b03d9697dde3ef3520f67d1d8166f7af7689551

wolverineav/networking-bigswitch,openstack/networking-bigswitch,stackforge/networking-bigswitch,wolverineav/networking-bigswitch,stackforge/networking-bigswitch,openstack/networking-bigswitch