(nxtitemp, trade_getitem, trade_desc, trade_check_item_ok, nxtitem,

oprange, show_mission, nameofitem, build_mission_list_type,
unit_map, xdvisible, trdswitchown, ontradingblock, trad, check_trade,
unit_type_name, start_stop_unit, scut, scra, mission, multifire,
perform_mission, fuel, NSC_GENITEM): Replace struct genitem with
struct empobj.  Remove genitem.h and create a new file empobj.h.
Replace multiple instances of unions of ef_type structures with
one standard union empobj_storage which is a superset of the individual
instances.

src/lib/update/nxtitemp.c

@@ -39,7 +39,6 @@
 #include "land.h"
 #include "nsc.h"
 #include "file.h"
-#include "genitem.h"
 #include "player.h"
 #include "update.h"
 #include "gen.h"
@@ -48,7 +47,7 @@
 void *
 nxtitemp(struct nstr_item *np)
 {
-    struct genitem *gp;
+    struct empobj *gp;
     int selected;
 
     if (np->sel == NS_UNDEF)