networkTests: Reorganize parameters to dnsmasq and improve comments

Change-Id: I44127247bc4881ec5e9c7e6d9c1a48e1f254b2d8
Signed-off-by: Ondřej Svoboda <osvoboda@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/35862
Reviewed-by: Dan Kenigsberg <danken@redhat.com>