devel/py-simpleparse: turn mxBase dependency into option (default off)

- turn mxBase dependency into option (default off). It's only needed because of
  mx.DateTime and is not obligatory - f.e. pip didn't install it as dependency
- actualize comment and description
- bump PORTREVISION because of dependency change


git-svn-id: svn+ssh://svn.freebsd.org/ports/head@374905 35697150-7ecd-e111-bb59-0022644237b5
Update the stupidity fix after BSDPAN removal.

Noticed by:	antoine
Sponsored by:	Absolight


git-svn-id: svn+ssh://svn.freebsd.org/ports/head@374906 35697150-7ecd-e111-bb59-0022644237b5