Screenlock: Recognize keyrelease rather than keydown to avoid inadvertent exits

E.g. so now you distinctively have to press down the powerbutton three times
rather than holding (which is easy to do inadvertently in pocket) to exit
screenlock.

programs/sxmo_screenlock.c

@@ -6,6 +6,7 @@
 #include <unistd.h>
 #include <X11/keysym.h>
 #include <X11/XF86keysym.h>
+#include <X11/XKBlib.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 
@@ -177,7 +178,7 @@ readinputloop(Display *dpy, int screen) {
 
 		if (FD_ISSET(xfd, &fdset) && XPending(dpy)) {
 			XNextEvent(dpy, &ev);
-			if (ev.type == KeyPress) {
+			if (ev.type == KeyRelease) {
 				XLookupString(&ev.xkey, buf, sizeof(buf), &keysym, 0);
 				if (lastkeysym == keysym) {
 					lastkeyn++;
@@ -282,6 +283,7 @@ main(int argc, char **argv) {
 	if (!(dpy = XOpenDisplay(NULL)))
 		die("Cannot open display\n");
 
+	XkbSetDetectableAutoRepeat(dpy, True, NULL);
 	screen = XDefaultScreen(dpy);
 	XSync(dpy, 0);
 	getoldbrightness();