mod_wsgi should have python3 support.

it is desirable to parallel install the apache-mod_wsgi and apache-python3-mod_wsgi  packages.  We just don't want both modules to be run in the same apache instance.  This should be done by using conditionals in the apache conf file.

Additional info:

* The conflicts between mod_wsgi and python3-mod_wsgi should be removed.
* The conf file for python3-mod_wsgi should look something like this:
  # NOTE: mod_wsgi_python3 can not coexist in the same apache process as 
  # mod_wsgi (python2).  Only load if mod_wsgi is not already loaded.
 
  <IfModule !wsgi_module>
    LoadModule wsgi_module modules/mod_wsgi_python3.so
  </IfModule>

* The conf file for mod_wsgi should look something like this:
  # NOTE: mod_wsgi can not coexist in the same apache process as 
  # mod_wsgi_python3.  Only load if mod_wsgi_python3 is not
  # already loaded.
 
  <IfModule !wsgi_module>
    LoadModule wsgi_module modules/mod_wsgi.so
  </IfModule>




Reproducible: 

Steps to Reproduce: