(I_NONE, I_CIVIL, I_MILIT, I_SHELL, I_GUN, I_PETROL, I_IRON, I_DUST,

I_BAR, I_FOOD, I_OIL, I_LCM, I_HCM, I_UW, I_RAD, I_MAX): Turn macros
into enumeration constants.
(i_type): New.  Use where appropriate.  No functional changes, except
that I_NONE is now catched properly in a few places.

src/lib/commands/rese.c

@@ -116,7 +116,7 @@ rese(void)
 	    pr("The destination sector must be at least 60%% efficient.\n");
 	    return RET_OK;
 	}
-	if (CANT_HAPPEN((unsigned)comm.com_type > I_MAX)) {
+	if (CANT_HAPPEN(comm.com_type <= I_NONE || comm.com_type > I_MAX)) {
 	    pr("The goods have been eaten by a grue.");
 	    return RET_OK;
 	}