The previous tar support lacked the ability to track changes between tarball deploys. Critically, it also failed to be handled correctly when there was _also_ a git deployment done on the app, resulting in odd deployment states depending on the angles of the moon and the sun in the sky.
Rather than try to "fix" this through some hokey mechanism, importing the tar file contents into the git repository is preferred, as then the user can refer to the repository for commit history.
Additionally, we add support for non-tar files (tar.gz and zip), enabling deployments from systems that do not create tar files, such as Github (their tarball url is a tar.gz file).
Finally, this deprecates the tar plugin, and sets it to be removed in the next minor release (in addition to the tags plugin).
Closes#3458Closes#4207
The tags and tar plugins do not necessarily build from source, and running `ps:rebuild` can have some unexpected output in certain cases. Rather than try to handle that complexity - it's a lot - documenting the edge cases is the most appropriate way forward.
