Add web mixer with native input volume and output selection

scripts/check-build.sh

@@ -15,10 +15,11 @@ git clone -q --branch 5.5.2 "$PACKAGE_DIR/sources/shairport-sync-5.5.2.bundle" "
 )
 (
  cd "$BUILD_DIR/shairport-sync"
+ git apply "$PACKAGE_DIR/sources/shairport-native-volume.patch"
  autoreconf -fi
  ./configure --prefix=/usr/local --sysconfdir=/etc --with-alsa --with-soxr \
    --with-avahi --with-ssl=openssl --with-systemd-startup \
-   --with-systemdsystemunitdir=/etc/systemd/system --with-airplay-2
+   --with-systemdsystemunitdir=/etc/systemd/system --with-airplay-2 --with-dbus-interface
  make -j 1
  ./shairport-sync -V
 )