DAGOLDEN unified mega patch -- prepare/make, fix prereqs, recommends/suggests, default mirror

This patch includes all my work since Paris last year:

* prepare/make split (mst's work)
* fixing various prereq bugs
* refactor get/prepare/make/test/install shorcut logic
* recommends/suggests policies and support
* www.cpan.org as default mirror

I suggest it be merged to master so further work can build on it and if there any remaining bugs, we'll squash them as we go.