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/wintype.h

@@ -101,6 +101,7 @@ typedef struct glyph_map_entry {
 typedef struct gi {
     int glyph;            /* the display entity */
     int ttychar;
+    uint32 framecolor;
     glyph_map gm;
 } glyph_info;
 #define GLYPH_INFO_P struct gi
@@ -213,6 +214,22 @@ typedef struct win_request_info_t win_request_info;
 
 /* #define CORE_INVENT */
 
+/* In a binary with multiple window interfaces linked in, this is
+ * a structure to track certain interface capabilities that cannot be
+ * statically done at compile time. Some of them can be toggled and
+ * the core needs to know if they are active or not at the time.
+ */
+
+enum win_display_modes {
+    wdmode_traditional = 0,
+    wdmode_tiled
+};
+
+struct win_settings {
+    enum win_display_modes wdmode;
+    uint32 map_frame_color;
+};
+
 /* clang-format on */
 
 #endif /* WINTYPE_H */