BaseCoreFilter docstring and formating improved
BaseCoreFilter docstring and formating improved

Docstrings and log formating changed
according to pep8.

Change-Id: I837eb7cef86fe6202a2df58c71e9817953f4dd82

alaski/nova,cloudbase/nova,gooddata/openstack-nova,Juniper/nova,gooddata/openstack-nova,jianghuaw/nova,cloudbase/nova,mahak/nova,vmturbo/nova,mahak/nova,mikalstill/nova,hanlind/nova,Juniper/nova,mikalstill/nova,cloudbase/nova,rahulunair/nova,sebrandon1/nova,rahulunair/nova,rajalokan/nova,phenoxim/nova,rajalokan/nova,klmitch/nova,openstack/nova,vmturbo/nova,mahak/nova,vmturbo/nova,gooddata/openstack-nova,rajalokan/nova,hanlind/nova,alaski/nova,jianghuaw/nova,sebrandon1/nova,jianghuaw/nova,rahulunair/nova,Juniper/nova,klmitch/nova,rajalokan/nova,openstack/nova,hanlind/nova,gooddata/openstack-nova,klmitch/nova,vmturbo/nova,mikalstill/nova,phenoxim/nova,openstack/nova,jianghuaw/nova,klmitch/nova,Juniper/nova,sebrandon1/nova