x11: drop xscrnsaver use

It's an ancient X11 protocol extension that apparently nobody uses
anymore (desktop environments in particular have replaced it with
equally bad protocols that require tons of dependencies). Users keep
complaining about it being a required dependency.

The impact is likely minimal to none.

Fixes #4706 and other annoying people.

README.md

@@ -96,7 +96,7 @@ Example:
 Essential dependencies (incomplete list):
 
 - gcc or clang
-- X development headers (xlib, xrandr, xext, xscrnsaver, xinerama, libvdpau,
+- X development headers (xlib, xrandr, xext, xinerama, libvdpau,
   libGL, GLX, EGL, xv, ...)
 - Audio output development headers (libasound/ALSA, pulseaudio)
 - FFmpeg libraries (libavutil libavcodec libavformat libswscale libavfilter

video/out/x11_common.c

@@ -33,7 +33,6 @@
 #include <X11/XKBlib.h>
 #include <X11/XF86keysym.h>
 
-#include <X11/extensions/scrnsaver.h>
 #include <X11/extensions/dpms.h>
 #include <X11/extensions/Xinerama.h>
 #include <X11/extensions/Xrandr.h>
@@ -1908,22 +1907,9 @@ static void xscreensaver_heartbeat(struct vo_x11_state *x11)
     {
         x11->screensaver_time_last = time;
         sem_post(&x11->screensaver_sem);
-        XResetScreenSaver(x11->display);
     }
 }
 
-static int xss_suspend(Display *mDisplay, Bool suspend)
-{
-    int event, error, major, minor;
-    if (XScreenSaverQueryExtension(mDisplay, &event, &error) != True ||
-        XScreenSaverQueryVersion(mDisplay, &major, &minor) != True)
-        return 0;
-    if (major < 1 || (major == 1 && minor < 1))
-        return 0;
-    XScreenSaverSuspend(mDisplay, suspend);
-    return 1;
-}
-
 static void set_screensaver(struct vo_x11_state *x11, bool enabled)
 {
     Display *mDisplay = x11->display;
@@ -1931,8 +1917,6 @@ static void set_screensaver(struct vo_x11_state *x11, bool enabled)
         return;
     MP_VERBOSE(x11, "%s screensaver.\n", enabled ? "Enabling" : "Disabling");
     x11->screensaver_enabled = enabled;
-    if (xss_suspend(mDisplay, !enabled))
-        return;
     int nothing;
     if (DPMSQueryExtension(mDisplay, &nothing, &nothing)) {
         BOOL onoff = 0;

wscript

@@ -578,7 +578,6 @@ video_output_features = [
         'name': '--x11',
         'desc': 'X11',
         'func': check_pkg_config('x11',         '>= 1.0.0',
-                                 'xscrnsaver',  '>= 1.0.0',
                                  'xext',        '>= 1.0.0',
                                  'xinerama',    '>= 1.0.0',
                                  'xrandr',      '>= 1.2.0'),