[NEW] devel/pydio-packr: Pydio port of packr v1

Summary:
This is a fork of gobuffalo's packr v1 customized by pydio team.
Its sole purpose is to be used in building the www/pydio-cells port.

WWW: https://github.com/pydio/packr

Reviewed by: koobs
Differential Revision: https://reviews.freebsd.org/D30322