core: SearchExpression is now abstract
core: SearchExpression is now abstract

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