npm generic pipelines (with manifests)

[tpluscode]

Reusable and generic pipelines should be usable in two ways:

1. Standalone: by loading such a pipeline from the CLI by a node/http URL
2. Importing from another pipeline (#93)

A prerequisite for the latter will be a generic loader, similar to this

[tpluscode]

I've been thinking about this for the case of #98. There, we need the first, standalone style

Rather that addressing by an URL. I was thinking of automatically extending the CLI of barnard59 itself. For example, the "curl" pipeline could be part of barnard59-graph-store. The pipelines could be identified by URI ending in /put, /post etc, thus combining into a dynamic CLI usage

barnard59 graph-store put ...

The additional part would be automatically adding pipeline variables as command line flags...