fix bug #38401: xboard.texi doesn't build with texinfo-5.0 (tiny change)

xboard-4.7.0's documentation is not buildable with texinfo-5.0, it fails with a lot of error messages from makeinfo like
./xboard.texi:1026: @itemx must follow @item
makeinfo seems right, @itemx is not used as described in the texinfo manual.
Attached patch puts each item of the "Options" menu in it's own @subsection and formats the description of each item as a @table as neccessary. This way, xboard builds again and the manual doesn't look too bad.
Work-around for Xt selection bug

In some Xt implementations calling extend-end with 0 params causes a crash,
although the mmanual specifies this should default to a call with 'PRIMARY'.
The default selection is now explicitly mentioned in all extend-end calls.
Repair WinBoard compile error

__GITVERSION was not defined in WinBoard, as it was only defined with a
compiler flag by ./configure, which WinBoard does not use.
Add -backupSettingsFile option

For better configurability of WinBoard, an option is added to optionally
read a settings file, namely if no other settings file (other than the
master file) was read so far. This can be used to import settings from
a previous version, without destroying its settings file.
Make skipping of unknown option smarter

To make XBoard better resistant to the presence of disbanded or future
options in its settings file, encountering those is no longer a fatal error.
But the error recovery only consisted of skipping the rest of the line.
This fails badly on string options with a multi-line value, which is
enclosed by {braces}. We now detect that case, to skip to } instead.
Let popping up of WinBoard chatbox for channel open it

WinBoard now issues a +ch command for a channel when you pop up a chatbox
for that channel. A work-around is added for the fact that the public
FICS seems to ignore the first such command.
Fix of argument error

Oops. Pevious patch for skipping unknown multi-line arguments
was still buggy.
Updated Ukrainian translations
Updated German translation
Fix vertical sizing of GTK board

The clipping of the boad at the bottom was due to resizing of the clock
height when we first write it with a big font. This patch delays calculation
of the final size until after the clock height changes.
Fix buffer overflow in feature parsing

String features (variants, egt, myname and option) relied on a buf[MSG_SIZ]
for processing their value. The Nebiyu engine had combobox options that
required more than that. All string features are now stored in allocated
memory rather than in static arrays, and StringFeature allocates a buffer
of sufficient size for them. Only limitation now is the low-level input
buffer in the InputSource threads, whih is a static buffer of 4096
(=INPUT_SOURCE_BUF_SIZE) characters.
Accept setup command for non-standard board size

The code to test if board-size is standard for the current variant
has been moved to a subroutine, to allow its calling when receiving
a "setup" command from the engine.
Fix fatal error on unsupported board size

When a board size unsupported by the engine was requested through the
New Variant dialog, this was discovered while the dialog was still up,
causing the error message to pop up as a child of the New Variant dialog,
so that it would immediately be taken down as the latter closed.
As a result it could not be confirmed, so that XBoard would not exit, and
was left in a pathologic state (ignoring window-close). This is fixed
by performing Reset (which detects the error) after PopDown of New Variant.
Fix GTK box popup

Key values > 255 are used for PgUp, PgDown etc., so to pop up only on
printables needs a two-sided test.
Let XBoard -autoBox option also affect move type-in
Fix spurious popup after batch-mode Analyze Game

A batch analysis of games was not properly terminated, because the game
mode was tested after it had already been changed. No oldGameMode is
tested in stead.
Fix saving of analyzed game

Anotated games after batch-mode Analyze Game were not auto-saved,
because the GameEnds() call supposed to do that was called with a NULL
argument for resultDetails. Now it is called with the resultDetails as
pre-existing in the gameInfo, or an empty string if none exist. This bug
was masked by the fact that in standard game ends (mate, etc.) the
analyzing engine would declare game end and supply a message.
 Also makes a distinction between Analyze Game and regular Analyze mode
when resuming analysis after loading a game; only the former now would
trigger a batch analysis.
Provide compatibility with Alien Edition setup command

The setup command of the Alien Edition has a board-size specifier
(possibly as prefix on a parent-variant name) between pieceToCharTable
and FEN. The regular version would choke on that, precluding engines
designed for the Alien protocol extension to have their setup processed
when running under regular XBoard. This patch makes it skip the extra info.
Fix quoting of book name in tourney file

The argument of -polyglotBook was written to the tourney file unquoted,
which effectively made it disappear if it was an empty or blank string.
Fix disappearence of pieces that were moved illegally

Dragging damages the from-square, but it is not marked as such, because
selective board redraws to update highlights and such would draw the piece
that is really still there, making it flash on the from-square before
the position after the move is drawn. This, however, backfires when the
move was illegal, as then there is no draw of a new position, and the
from-square stays empty. For now this is solved by making DisplayMoveError()
order a total redraw. (As this is rare, only done in case of an error,
and might even throw up a pop-up, the performance cost of this is acceptable.)