webadmin: Add Network QoS to webadmin

Add UI of Network QoS to webadmin

see: http://wiki.ovirt.org/Features/Design/Network_QoS

Change-Id: Iaf3e26c09b41306452302e36710658393b7b55b8
Signed-off-by: Ofri Masad <omasad@redhat.com>