Added --nostereo option

Ability to disable stereo panning effect (e.g., paint brush, UI
elements sound effect feedback, etc.), useful for users with
hearing impairment in one ear, or situations where one speaker or
headphone is being used.  Use "--nostereo" command-line option
or "nostereo=yes" config. file option.

src/manpage/tuxpaint.1

@@ -1,5 +1,5 @@
-.\" tuxpaint.1 - 2019.09.12
-.TH TUXPAINT 1 "12 September 2019" "0.9.24" "Tux Paint"
+.\" tuxpaint.1 - 2019.09.21
+.TH TUXPAINT 1 "21 September 2019" "0.9.24" "Tux Paint"
 .SH NAME
 tuxpaint -- "Tux Paint", a drawing program for young children.
 
@@ -23,6 +23,8 @@ tuxpaint -- "Tux Paint", a drawing program for young children.
 .br
 [\-\-nosound]
 .br
+[\-\-nostereo]
+.br
 [\-\-noquit]
 .br
 [\-\-noprint]
@@ -153,6 +155,8 @@ tuxpaint -- "Tux Paint", a drawing program for young children.
 .br
 [\-\-sound]
 .br
+[\-\-stereo]
+.br
 [\-\-quit]
 .br
 [\-\-print]
@@ -277,7 +281,7 @@ orientations are both supported.  (Also see \-\-orient, below.)
 
 .TP 8
 .B \-\-orient=landscape \-\-orient=portrait
-If \-\-orient=portraitis set, asks \fITux Paint\fP to swap the WIDTH and HEIGHT
+If \-\-orient=portrait is set, asks \fITux Paint\fP to swap the WIDTH and HEIGHT
 values it uses for windowed or fullscreen mode, without having to actually
 change the WIDTH and HEIGHT values in the configuration file or on the
 command-line. (This is useful on devices where the screen can be rotated,
@@ -287,6 +291,10 @@ e.g. tablet PCs.)
 .B \-\-nosound \-\-sound
 Disable or enable (default) sound.
 
+.TP 8
+.B \-\-nostereo \-\-stereo
+Disable or enable (default) stereo panning support.
+
 .TP 8
 .B \-\-noquit \-\-quit
 Disable or enable (default) the on-screen \fIQuit\fP button and \fIEscape\fP