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/wmgenmenu.1

@@ -1,29 +1,29 @@
-.TH "wmgenmenu" "1" "15 August 2011"
+.TH wmgenmenu 1 "15 August 2011"
 .SH "NAME"
 \fBwmgenmenu\fR \- Writes a menu structure usable as
 ~/GNUstep/Defaults/WMRootMenu to stdout
 .PP
 .SH "SYNOPSIS"
-.B wmgenmenu \fR[ \fI\-\-options \fR]
+.B wmgenmenu
+.RI [ options ]
 .PP
 .SH "DESCRIPTION"
-\fBwmgenmenu \fR\- Writes a menu structure usable as
-~/GNUstep/Defaults/WMRootMenu to stdout
+\fBwmgenmenu\fR writes a menu structure usable as
+~/GNUstep/Defaults/WMRootMenu to stdout.
+
+The output format is a \fIPropList\fP.
 .PP
 .SH "OPTIONS"
 .TP
 .B \-\-help
-\fRdisplay this help and exit
+print a help message with the list of options
 .TP
 .B \-\-version
-\fRoutput version information and exit
-.TP
-.B \-\-h
-\fRlike \-\-help
-.TP
-.B \-\-v
-\fRlike \-\-version
+print the version of Window Maker from which the program comes
 .PP
+.SH "BUGS"
+The program is using a built-in structure and list of applications, which means it cannot discover
+new programs, but it filters the programs that cannot be found in the \fBPATH\fP.
 .SH "AUTHOR"
 wmgenmenu is a part of Window Maker. It was written by Carlos R. Mafra and
 Tamas TEVESZ.