Change some command keys

Change 'v' from #versionshort to #chronicle.
Change 'V' from #history to #versionshort.
History can still be accessed either directly with the extended command,
or via the help menu.
Versionshort now accepts the m-prefix, and then shows the longer version.

src/version.c

@@ -157,6 +157,9 @@ doversion(void)
 {
     char buf[BUFSZ];
 
+    if (iflags.menu_requested)
+        return doextversion();
+
     pline("%s", getversionstring(buf, sizeof buf));
     return ECMD_OK;
 }