Message bus additions for RHEL/CentOS/Fedora distributions

Added the default 'qpid' implementation details for neutron.conf as this was omitted and reported upstream.

Change-Id: I527751f8380dd1883fb9f1159089f7050130fc74
Closes-bug: #1258292
Merge "Message bus additions for RHEL/CentOS/Fedora distributions"