Add menus to Linux character editor

Patch from @x-qq

src/pcedit/pc.graphics.hpp

@@ -1,5 +1,7 @@
+#include <SFML/Graphics.hpp>
 
 void init_main_buttons();
 void Set_up_win ();
 void redraw_screen();
 void do_button_action(short which_pc,short which_button);
+sf::Vector2f translate_mouse_coordinates(sf::Vector2i const point);