Complete libpkg and create new pkg tools

by David Forsythe for The FreeBSD Project

The goal of this project is to complete libpkg (created during GSoC 2009) and build a stable set of pkg tools with it. This includes adding any features to libpkg that are needed by the FreeBSD pkg tools and are not present in the library, adding testing to libpkg, and creating any pkg tools that could benefit from libpkg. Additionally, this project will try and keep track of the revisions to pkg_install being made by others, and changes made to the standards of packages on FreeBSD.