introduce support for coloring the frame behind a map location

Also includes support by paxed for polearm targeting using the
frame color.

Also renames USE_TILES to TILES_IN_GLYPHMAP which is a more
accurate description.

Not all window interfaces have full support for the color framing
of the background square yet.

MS-DOS needs further work (to bring it to both VESA and VGA, with
and without tiles.

Windows GUI is missing support.

X11 and Qt have been started, but may require further refinement.

include/wincurs.h

@@ -129,10 +129,10 @@ extern void curs_destroy_all_wins(void);
 #ifdef ENHANCED_SYMBOLS
 extern void curses_putch(winid wid, int x, int y, int ch,
                          struct unicode_representation *u, int color,
-                         int attrs);
+                         int framecolor, int attrs);
 #else
 extern void curses_putch(winid wid, int x, int y, int ch, int color,
-                         int attrs);
+                         int framecolor, int attrs);
 #endif
 extern void curses_get_window_size(winid wid, int *height, int *width);
 extern boolean curses_window_has_border(winid wid);