patch 8.0.1639: libvterm code lags behind master

Problem:    Libvterm code lags behind master.
Solution:   Sync to head, solve merge problems.
diff --git a/src/libvterm/bin/vterm-ctrl.c b/src/libvterm/bin/vterm-ctrl.c
index 2568ee6..e43297c 100644
--- a/src/libvterm/bin/vterm-ctrl.c
+++ b/src/libvterm/bin/vterm-ctrl.c
@@ -53,6 +53,7 @@
   "curblink [off|on|query]",
   "curshape [block|under|bar|query]",
   "mouse [off|click|clickdrag|motion]",
+  "reportfocus [off|on|query]",
   "altscreen [off|on|query]",
   "bracketpaste [off|on|query]",
   "icontitle [STR]",
@@ -81,9 +82,9 @@
   return ret;
 }
 
-static void await_c1(int c1)
+static void await_c1(unsigned char c1)
 {
-  int c;
+  unsigned char c;
 
   /* await CSI - 8bit or 2byte 7bit form */
   int in_esc = FALSE;
@@ -340,6 +341,9 @@
         printf("\x1b[?1003h"); break;
       }
     }
+    else if(streq(arg, "reportfocus")) {
+      do_dec_mode(1004, getboolq(&argi, argc, argv), "reportfocus");
+    }
     else if(streq(arg, "altscreen")) {
       do_dec_mode(1049, getboolq(&argi, argc, argv), "altscreen");
     }