Add friendly event hints for logging
Add friendly event hints for logging

When creating a network log with the '--event' parameter, it is
impossible to know which parameter values can be specified, and it
is necessary to add a prompt.

Change-Id: I6aa4f95b650cdc7b04e74b851a78a2ae42fc288a

openstack/python-neutronclient,openstack/python-neutronclient