doc: updated man pages for many tools

This patch perform simple fixes to the man pages and tool help page:
 - minor style updates, to get cleaner pages
 - option re-ordering, to have them in alphabetic order (easier to search for)
 - consistency updates for descriptions and number of dash
 - spell-checking

The biggest changes are:
 - wmagnify: the option 'vdisplay' was not documented at all;

 - getstyle: the list of attributes that are taken for the Style are now
described in their own section to clarify the page;

 - setstyle: the help page left thinking that the file argument was
optional, which is not the case;

 - wdread: as the Exit Code may be useful, and it is not unusable, it is
now documented;

 - wmgenmenu: added information about how the content of the menu is
generated;

 - wmsetbg: added a section about dithering/best-match because as nowadays
most screens are in True Color, the reason for the option may not be clear.

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>

doc/wmagnify.1x

@@ -1,10 +1,11 @@
-.TH WMAGNIFY 1 "March 22, 2006" "" "User Commands"
+.TH wmagnify 1x "March 22, 2006"
 
 .SH NAME
 wmagnify \- magnify parts of the screen
 
 .SH SYNOPSIS
-\fBwmagnify\fR [\fIoptions\fR]
+.B wmagnify
+.RI [ options ]
 
 .SH DESCRIPTION
 \fBwmagnify\fR is a tool which allows you to magnify parts of the screen. The
@@ -12,36 +13,43 @@ main difference from \fBxmag\fR is that the image is refreshed automatically,
 following the cursor on the screen.
 
 .SH OPTIONS
-The following command line options are available.
+The following command line options are available:
 .TP
-\fB\-m\fR \fIfactor\fR
+.BR \-display " \fIdisplay\fP"
+Show the magnified area on this \fIdisplay\fR.
+.TP
+.B \-\-help
+print a help message with the list of options.
+.TP
+.BR \-m " \fIfactor\fP"
 Change the magnification factor, default is 2. You can change this also while
 running the program, using the keys described below.
 .TP
-\fB\-r\fR \fIdelay\fR
+.BR \-r " \fIdelay\fP"
 Change the refresh delay, in milliseconds. Default is 200.
 .TP
-\fB\-display\fR \fIdisplay\fR
-Use \fIdisplay\fR instead of the default one.
+.BR \-vdisplay " \fIdisplay\fP"
+Take the area to be magnified from this \fIdisplay\fP instead of using the same display as for visualisation.
 
 .SH KEYS
 The following keys can be pressed while \fBwmagnify\fR is running to change its
 behaviour.
 .TP
-\fB1,2,3,4,5,6,7,8,9\fR
+.BR 1 , 2 , 3 , 4 ,  5 , 6 , 7 , 8 , 9
 Change the magnification factor.
 .TP
-\fB<space>, f\fR
+.BR <space> ", " f
 Freeze the camera, making it magnify only the current position.
 .TP
-\fBn\fR
+.B n
 Create a new window.
 .TP
-\fBm\fR
-Show/hide the pointer hotspot mark.
+.B m
+Show/hide the pointer hot spot mark.
 
 .SH SEE ALSO
-\fBxmag(1)\fR, \fBwmaker(1)\fR
+.BR xmag (1),
+.BR wmaker (1)
 
 .SH AUTHOR
 This manual page was written by Andrea Bolognani <eof@kiyuko.org> for the