v2.2.0

This version can install ( via 'make install' on the master branch ) on a Red Hat system, and run Debian based containers there. Note that support for creating Red Hat based images is NOT present yet as there are quite a few runtime differences between it and Debian.

This release also involved making the 'master' branch Makefile a bit more robust, and updating the README files.

sha1sum of the attached 2.2.0-1 deb is:
12a6a9a9be2553946353116a84e28d62091f170d ../due_2.2.0-1_all.deb