Added GoodGetModule to the GoodGet CLI/library, representing the GoodGet module itself, exposing the pattern we use for lightweight dependency injection.
Added class Feed to GoodGet, representing a NuGet feed.
Added FeedPackages class, representing a set of packages to be synchronized with a given feed.
Extended the FeedPackages constructor to allow instances to be optionally initialized with a given set of packages.
Added the principal highest level abstraction exposing the functionality of the GoodGet executable/library, the PackagesFolder class.