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.

win/tty/termcap.c

@@ -1282,6 +1282,9 @@ int color;
         xputs(hilites[color]);
 }
 
+#if 0
+/* Replaced by src/windows.c general proc or a macro in 3.6.3 */
+
 /* not to be confused with has_colors() in unixtty.c */
 int
 has_color(color)
@@ -1316,7 +1319,7 @@ int color;
     return hilites[color] != (char *) 0;
 #endif
 }
-
+#endif /* 0 */
 #endif /* TEXTCOLOR */
 
 #endif /* TTY_GRAPHICS && !NO_TERMS */