has_color() performance fixes

Performance profiling showed that multiple strcmpi() calls were
occurring each and every time a character was going to the map.

This update:
- honors the WC_COLOR capability
- It allows a window-port to control individual color availability should the window-port wish to do so.
- Makes checking on the individual colors for the active window-port is a straightforward table lookup at the CLR_ offset.

iflags.use_color remains a master on/off switch for use of color, regardless of the capability
compiled into the game (default TRUE).

The has_color() routine, which is now a shared routine in src/windows.c, could likely be made
into a simple macro to eliminate the function call, but this update does not go that far.

This hits a lot of port files due to the window-port interface change, mostly cookie-cutter.

sys/mac/macwin.c

@@ -3251,7 +3251,9 @@ struct window_procs mac_procs = {
     WC_COLOR | WC_HILITE_PET | WC_FONT_MAP | WC_FONT_MENU | WC_FONT_MESSAGE
         | WC_FONT_STATUS | WC_FONT_TEXT | WC_FONTSIZ_MAP | WC_FONTSIZ_MENU
         | WC_FONTSIZ_MESSAGE | WC_FONTSIZ_STATUS | WC_FONTSIZ_TEXT,
-    0L, mac_init_nhwindows,
+    0L,
+    {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},   /* color availability */
+    mac_init_nhwindows,
     mac_unimplemented, /* see macmenu.c:mac_askname() for player selection */
     mac_askname, mac_get_nh_event, mac_exit_nhwindows, mac_suspend_nhwindows,
     mac_unimplemented, mac_create_nhwindow, mac_clear_nhwindow,