Introduce /redraw command

`/redraw` command allows resolve problem for usual users,
as well as developers.

Incredibly useful when debugging with something that
can trash out the output, like GDB.

Not to mention many asynchronous commands that can break the UI
at any point.

src/command/cmd_funcs.c

@@ -9727,6 +9727,14 @@ cmd_correct_editor(ProfWin* window, const char* const command, gchar** args)
     return TRUE;
 }
 
+gboolean
+cmd_redraw(ProfWin* window, const char* const command, gchar** args)
+{
+    ui_resize();
+
+    return TRUE;
+}
+
 gboolean
 cmd_silence(ProfWin* window, const char* const command, gchar** args)
 {