CHANGE_COLOR palette option adjustments

It was too early to call the windowport change_color() routine
while processing the config file. The windowport was not yet
fully operational.

Now the palette option processing will just place the rgb
value into the appropriate ga.altpalette[CLR_MAX] entry.

init_sound_disp_gamewindows(void) [allmain.c] calls
change_palette() [coloratt.c] and it will call the windowport
change_color() function for each ga.altpalette[] entry that
has been set.

Notes:
The rgb values stored in ga.altpalette[] have the NH_ALTPALETTE bit set
so that the rgb value of 0 can be stored and be distinguishable from
a "not set" entry.

The NH_ALTPALETTE bit is cleared from the rgb value in change_palette()
prior to calling the windowport change_color() function.

The syntax for palette is colorname/r-g-b.
For example: palette:black/12-12-12

colorname must be one of the NH_BASIC_COLOR names or a suitable
alias for one of those 16 entries.

Some of the windowport CHANGE_COLOR functions had the wrong parameters,
perhaps due to bitrot. Those have been corrected to match the prototype.

src/allmain.c

@@ -667,6 +667,13 @@ init_sound_disp_gamewindows(void)
         SoundAchievement(0, sa2_newgame_nosplash, 0);
     }
 
+#ifdef CHANGE_COLOR
+    /* init_nhwindows() has already been called, so before
+       creating the windows, check to see if there are any
+       palette entries to alter */
+    change_palette();
+#endif
+
     WIN_MESSAGE = create_nhwindow(NHW_MESSAGE);
     if (VIA_WINDOWPORT()) {
         status_initialize(0);