added commandline option for stereo buffers to documentation

Documentation/DeveloperHelpSources/options.docu

@@ -14,6 +14,7 @@
  * -profile < compat | core >   : request Compatibility or %Core context ( Default = %Core )\n
  * -glVersion <int.int>           : request specified OpenGL version (Default = 3.2)\n
  * -samples <int>               : request MSAA with <int> samples (Default = 16)\n
+ * -glStereo <true | false>	: request creation of stereo buffers
  * \note The OpenGL command line parameters override stored settings temporarily. To permanently store an OpenGL setting, use the options dialog.
  *
  * Log options:\n