core: Fix service & item path conflict
core: Fix service & item path conflict

Since our HTTP server uses the same SoupServer for streaming items as
GUPnP does for serving description files, we need to change the (external)
paths of services to not conflict with that of our items.

GNOME/rygel,Tarnyko/rygel,Pelagicore/Media-Manager-Rygel-patched,Pelagicore/Media-Manager-Rygel-patched,GNOME/rygel,Pelagicore/Media-Manager-Rygel-patched,GNOME/rygel,luisbg/rygel,jku/rygel,jku/rygel,Tarnyko/rygel