Initial release

This is an update of the first release of XProc-Z, fixing a bug where an absolute path in the Java source meant that the app would only run if installed in the "right" place.

In brief: XProc-Z always runs the pipeline xproc/xproc-z.xpl - currently this just imports the pipeline library "visualize-distribution.xpl" and runs the pipeline defined therein called "visualize-distribution".