display version and build info at startup (trunk only)

Tested on the unix port; I've updated as many other ports as I can figure
out but they're not tested.  See window.doc for info on the changed banner
lines.  Also adds the ability to override the generic "Unix" port - used now to get
"MacOSX" into the version line instead of "Unix" (so we don't scare people who don't
know what's going on).

sys/wince/mhmain.c

@@ -11,6 +11,7 @@
 #include "mhmsgwnd.h"
 #include "mhcmd.h"
 #include "mhmap.h"
+#include "date.h"
 #include "patchlevel.h"
 
 #define MAX_LOADSTRING 100
@@ -996,7 +997,8 @@ LRESULT CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
 							NH_A2W(
 								COPYRIGHT_BANNER_A "\n"
 								COPYRIGHT_BANNER_B "\n"
-								COPYRIGHT_BANNER_C,
+								COPYRIGHT_BANNER_C "\n"
+								COPYRIGHT_BANNER_D,
 								wbuf,
 								NHSTR_BUFSIZE
 							) );