Extract cljs port of puget

[plexus]

As part of porting deep-diff to clojurescript, we ported Puget to ClojureScript. Sadly this version is not compatible with upstream puget, since we can't do type dispatching in the same way. This also means that people need to explicitly add print handlers for custom types (although apparently there's an option to fall back to the regular printer, we should enable that).

Having puget available in ClojureScript for rendering of cljs data structures is very useful, and we should pull that out into its own lib/artifact.