Collapse all xlib plugins under --enable-x11

except those that have their own --enable-* switch.

configure.ac

@@ -3963,7 +3963,9 @@ AC_ARG_ENABLE(x11,
 ])
 
 CPPFLAGS="${CPPFLAGS_save} ${X_CFLAGS}"
-AC_CHECK_HEADERS(X11/Xlib.h, [
+
+AS_IF([test "${enable_x11}" != "no"], [
+  AC_CHECK_HEADERS(X11/Xlib.h, [
     VLC_ADD_PLUGIN([x11_screen])
     VLC_ADD_CPPFLAGS([x11_screen],[${X_CFLAGS}])
     VLC_ADD_LIBS([x11_screen],[${X_LIBS} ${X_PRE_LIBS} -lX11])
@@ -3981,10 +3983,9 @@ AC_CHECK_HEADERS(X11/Xlib.h, [
     VLC_ADD_LIBS([x11],[${X_LIBS} ${X_PRE_LIBS} -lX11 -lXext])
     VLC_ADD_CPPFLAGS([x11],[${X_CFLAGS}])
   ])
-])
+  ])
 
 dnl Check for DPMS
-AS_IF([test "${enable_x11}" != "no"], [
   AC_CHECK_HEADERS(X11/extensions/dpms.h, [
     AC_MSG_CHECKING(for DPMSInfo in X11/extensions/dpms.h)
     AC_EGREP_HEADER(DPMSInfo,X11/extensions/dpms.h,[