* Correction of the "parameters" accessibility problem in the Go mapper
The "parameters" attributes of the GoPythonMapper class instance was
not accessible from the "output_rst" function used to create the .rst
file. Thanks to this correction, the parameters are now accessible.
* Enhance the template used to genertae the .rst file from the .go source file
This modification allows to create a .rst file compatible with the
last version of Sphinx. Without this correction, the creation of documentation
was not possible. A "make html" command lead to an "AssertionError" Exception.
With better formatting of domain output, separation by heading is redundant.
Also, secondary header for page title might not be necessary with correct domain
output of package objects.
