Integrate dmenu as a preloaded zero-lag DWM plugin (dmenu.so)

overlay/rootfs/usr/bin/sxmo_dmenu.sh

@@ -2,8 +2,6 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 # Copyright 2022 Sxmo Contributors
 
-. sxmo_common.sh
-
 unalias dmenu 2>/dev/null || true
 
 case "$1" in
@@ -12,10 +10,11 @@ case "$1" in
     shift
     ;;
   "isopen")
-    exec pidof -s dmenu >/dev/null
+    [ -e /tmp/dwm_plugin_dmenu.active ]
+    exit $?
     ;;
   "close")
-    pkill dmenu 2>/dev/null || true
+    dmenu close 2>/dev/null || true
     exit 0
     ;;
 esac