Adding support for archives.
Adding proper support for archives and gmock support.
Adding coroutine.mk and using it.
Performing some refactoring for basic artifact functionality.
Adding first real unit test.
Actually running a unit test.  Hollagit status!
Fixing bug which object_id::is_null was backwards.
Ignoring IDE specific project files.
Artifacts are tested and using static polymorphism (dependency injection).