Adding two new functions (UpnpSendAdvertisementLowPower and
UpnpUnRegisterRootDeviceLowPower) which can be used to specify values
for the three SSDP headers defined by UPnP Low Power. Those headers are
Powerstate, SleepPeriod and RegistrationState.
(cherry picked from commit 98e4f938d63226bcb623dd7d9cd1855482318534)
4b82bb7baf