Add a couple of controls (kill, zoom) to default pane-status-format.

Will be more to come with floating panes. From Dane Jensen in GitHub
issue 4981.

key-bindings.c

@@ -467,6 +467,10 @@ key_bindings_init(void)
 		"bind -n MouseDown1Status { switch-client -t= }",
 		"bind -n C-MouseDown1Status { swap-window -t@ }",
 
+		/* Mouse button 1 down on default pane-border-format */
+		"bind -n MouseDown1Control9 { display-menu -t= -xM -yM -O -T 'Kill pane #{pane_index}?' 'Yes' 'y' { kill-pane -t= } 'No' 'n' {}}",
+		"bind -n MouseDown1Control8 { resize-pane -Z }",
+
 		/* Mouse wheel down on status line. */
 		"bind -n WheelDownStatus { next-window }",
 

options-table.c

@@ -1305,7 +1305,14 @@ const struct options_table_entry options_table[] = {
 	  .type = OPTIONS_TABLE_STRING,
 	  .scope = OPTIONS_TABLE_WINDOW|OPTIONS_TABLE_PANE,
 	  .default_str = "#{?pane_active,#[reverse],}#{pane_index}#[default] "
-			 "\"#{pane_title}\"",
+			 "\"#{pane_title}\""
+			 "#{?#{mouse},"
+				"#[align=right]"
+				"#[range=control|8]["
+					"#{?#{window_zoomed_flag},u,z}"
+				"]#[norange]"
+				"#[range=control|9][x]#[norange]"
+			",}",
 	  .text = "Format of text in the pane status lines."
 	},