made discoexplorer() a static member of UPnPDeviceDirectory, as I found no way to get rid of the warnings when it is a friend static non-member
control:mediarenderer: dont create the services until needed
adjust log verb levels
control: dont redecode already decoded xml...
OpenHome was not completly switched off when the option was off. + err messages
oh cache save: write to tmp + rename instead of thrashing the main cache file