Make proper and neotoma development-time only dependencies

Hi there,

These patches would make it easier for us to integrate erlware_commons into Opscode's erchef code base and I suspect would be useful to other consumers of erlware_commons as well.

The basic idea is not to force downstream projects to pull in dependencies that are not needed by erlware_commons at runtime.

In the case of proper, this is only needed for running tests and folks might wish not to have it come along for the ride due to licensing concerns.

For neotoma, the issue is more likely to be depending on different versions of that code base to generate parsers.

The patches include a few unrelated Makefile fixes and detail of the dev-only mechanism is in the last commit message. The core idea was taken from Paul Davis author of jiffy.