address github issue #987 - curses: arrow keys

Issue reported by jeremyhetzler:  left and right arrows produced
unexpected characters when trying to use them to edit text that is
being entered.

The curses interface converts arrow keys and function keys related
to the keypad into movement keys (hjkl or 4286 depending on the
number_pad setting).  But it was doing that all the time, not just
when nethack wanted movement keys.  This extends the existing
program_state.getting_a_command flag to getdir() so that it can be
used for controlling that in addition to 'altmeta' support.

Typing an arrow when interacting with the map (actual command or
getpos, now getdir too) will still work.  Typing one when making a
wish or naming a pet will issue a beep and be treated as if '\0' had
been typed, and that normally gets treated as if ESC had been typed.
[Possible room for improvement there.  Losing the whole text when
trying to back up a character feels a bit harsh.]

Treating left arrow as escape rather than as h or 4 will probably be
enough to train players not to try to edit text with it after they
get burned by that a time or two.

Bonus fix:  curses' keystroke conversion only supported traditional
number_pad behavior, not the inverted phone number pad layout.

Closes #987

doc/fixes3-7-0.txt

@@ -409,7 +409,6 @@ spells that require a target spot rather than a direction (like skilled
 prevent wish request "death wand" from matching Death monster and producing a
 	random wand instead of a wand of death
 grammar bit: "you hear a [AEF] note squeak in the distance" (should be "an")
-curses interface failed to honor menu_xxx option settings for menu interaction
 during engraving, spaces were counted instead of non-spaces [later: affected
 	code is gone, removed when engraving was converted into an occupation]
 when an explosion scatters objects, make any that fly over sinks stop there
@@ -1586,6 +1585,7 @@ curses: sometimes entering a count during menu selection caused the menu to
 	more digits typed followed by non-digit); in-out menu was still active
 	but no longer displayed
 curses: support backspace/delete when entering a count during menu selection
+curses: was failing to honor menu_xxx option settings for menu interaction
 curses: make extended command prompt behave more sensibly
 curses: if a menu of objects contains at least one iron ball, and player is
 	not already in the midst of entering a count, recognize '0' as a
@@ -1593,6 +1593,9 @@ curses: if a menu of objects contains at least one iron ball, and player is
 curses: obey timed_delay option
 curses: support tty-style extended role/race/&c selection at start of new game
 curses: implement mark_synch() and wait_synch()
+curses: only convert arrow keys to hjkl or 4286 if nethack wants a direction
+curses: conversion of arrows and other numpad-related function keys to digit
+	ignored phone-layout setting (inverted up/down) of the num_pad option
 macOS: Xcode project was failing to build if the path to the NetHack source
 	tree contained a space; the issue was within some shell script code
 	contained within the project