one template -> multiple PMS XMLs, cleaned navigation, new Channels collection

XMLConverter
- prepare CommandClass for multiple PMS XML storage
- new cmd {{ADDXML()}} to load additional PMS XML source
- upgrade COPY, GETKEY to pull from selectable PMS XML
plexconnect.xml
- combine all channels into one, prepare for myplax, settings/info
Channels.xml
- new main channels page - combine /video, /music, /photos
ChannelsVideo.xml
- renamed original Channels.xml
TODO: update "oldmenu"