add triggerhappy hotkey daemon

Triggerhappy is a lightweight hotkey daemon that can launch arbitrary commands
on input events. It supports the hotplugging of devices and the processing of
key combinations.

Signed-off-by: Stefan Tomanek <stefan.tomanek+openwrt@wertarbyte.de>

utils/triggerhappy/files/triggerhappy.hotplug

@@ -0,0 +1,15 @@
+#!/bin/sh
+THD_SOCKET=/tmp/triggerhappy.socket
+[ -S "$THD_SOCKET" ] || exit
+
+case "$ACTION" in
+	add)
+		DEVICE="/dev/$DEVNAME"
+		[ -c "$DEVICE" ] || exit
+		# offer device to triggerhappy daemon
+		/usr/sbin/th-cmd --socket "$THD_SOCKET" --add "$DEVICE"
+	;;
+        remove)
+		# nothing to do
+	;;
+esac