'O' assistance

I don't care for this very much at all, but making it shorter will
reduce its usefullness.  It addresses one of the struggles exhibited
in the "a man and his cat" youtube video, where he was baffled when
selecting booleans didn't change their values and he later used Esc
instead of Enter after eventually finding number_pad.

This inserts some explanatory text (around three dozen lines,
unfortunately) at the start of 'O's menu.  Some of it is general menu
stuff, some is specific options stuff, and some attempts to fend off
various bug reports about options that do or don't persist across
save and restore or RC revisions that seem to have no effect.

The new introductory text can be disabled by turning off cmdassist.
Players who already do that don't need to see this.  Many who ignore
cmdassist and occasionally endure an outburst of compass directions
are likely to be goaded into turning it off.  I hope we won't need a
new 'optassist' for players who want to skip this but leave cmdassist
in general on.

It doesn't attempt to address his attempt to use arrow keys (possibly
arrows overloaded on number pad keys, or perhaps just digits on the
number pad while numpad mode was off) to navigate the menu then having
the Windows port 'helpfully' change those into hjkl which resulted in
selecting and subsequently unintentionally toggling some options on
the first page.  One was 'color' which he did notice and then re-run
'O' to successfully toggle it back on.  There was at least one other
which he either didn't notice to didn't both to reverse.

include/optlist.h

@@ -454,8 +454,8 @@ opt_##a,
 #ifdef STATUS_HILITES
     NHOPTC(statushilites, 20, opt_in, set_in_game, Yes, Yes, Yes, No, NoAlias,
                 "0=no status highlighting, N=show highlights for N turns")
-    NHOPTO("status hilite rules", o_status_hilites, BUFSZ, opt_in, set_in_game,
-           No, Yes, No, NoAlias, "edit status hilites")
+    NHOPTO("status highlight rules", o_status_hilites, BUFSZ, opt_in,
+           set_in_game, No, Yes, No, NoAlias, "edit status hilites")
 #else
     NHOPTC(statushilites, 20, opt_in, set_in_config, Yes, Yes, Yes, No,
                 NoAlias, "highlight control")