Message recall window extensions

by <Someone>

(the following text accompanies the patch at <Someone>'s web page)

add more configurability to the new msg_window option of [..]3.4.0.
It allows the configuration option to take an optional parameter to
specify the style of message history display to use.

allows the following configuration options:

msg_window:s - single message (as was the default in 3.3.0)
msg_window:c - combination; two messages in 'single', then as 'full'
msg_window:f - full window; oldest message first
msg_window:r - full window reversed; newest message first

In the event of no parameter being provided,
the patch is compatible with the current 3.4.0 behaviour:
msg_window = 'full'
!msg_window = 'single'
msg_window can be configured for these options in the
Options menu (Shift-O)
msg_window stores the current window type in the non-persistent
iflags structure, which means that savefile/bones files should be
100% compatible with Vanilla, but at the disadvantage that your
customisations to msg_window will be replaced with your
defaults.nh (or ~/.nethackrc) value every time you restart a saved game.
Credits:

The patch draws inspiration (and code snippets) extensively
from <Someone>'s original msg_window patch, [...] as well as <Someone>'s code for reverse ordering implemented until recently in
Slash'em.

doc/Guidebook.tex

@@ -27,7 +27,7 @@
 \begin{document}
 %
 % input file: guidebook.mn
-% $Revision: 1.40 $ $Date: 2002/04/04 03:44:18 $
+% $Revision: 1.41 $ $Date: 2002/04/13 16:00:06 $
 %
 %.ds h0 "
 %.ds h1 %.ds h2 \%
@@ -40,7 +40,7 @@
 %.au
 \author{Eric S. Raymond\\
 (Extensively edited and expanded for 3.4)}
-\date{April 3, 2002}
+\date{April 20, 2002}
 
 \maketitle
 
@@ -2342,8 +2342,21 @@ The number of top line messages to save (and recall with `{\tt \^{}P}')
 (default 20). Cannot be set with the `{\tt O}' command.
 %.lp
 \item[\ib{msg\_window}]
-Use a screen-size window to show the previous messages with `{\tt \^{}P}'
-instead of showing them one at a time.  (Currently implemented for tty only.)
+Allows you to change the way recalled messages are displayed.
+(It is currently implemented for tty only.) The possible values are:
+
+%.sd
+%.si
+{\tt s} --- single message (the default prior to 3.4.0).\\
+{\tt c} --- combination, two messages as {\it single\/}, then as {\it full\/}.\\
+{\tt f} --- full window, oldest message first.\\
+{\tt r} --- full window, newest message first.
+%.ei
+%.ed
+
+For backward compatibility, no value needs to be specified (which
+defaults to {\it full\/}), or it can be negated (which defaults
+to {\it single\/}). 
 %.lp
 \item[\ib{name}]
 Set your character's name (defaults to your user name).  You can also