Added Pashua

Pashua is a tool for creating native Aqua dialog windows from
programming languages that have none or only limi­ted support for
graphic user inter­faces on Mac OS X. Currently, it supports
Apple­Script, Perl, PHP, Python, Groovy, Rexx, Ruby, shell scripts and
Tcl—and if your favourite language is not included in this list:
writing the glue code for communicating with Pashua is pretty simple.
Merge pull request #3002 from alebcay/pashua

Added Pashua