[keepalived] new plugin

Fixes #302.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
[ipvs,keepalived] fix misleading copyright header

I've been using firewalld.py as a template for new plugins; forgot
to fix the copyright header to have the correct authorship.

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>

Conflicts:
	sos/plugins/ipvs.py