Type constructor helpers

[bobby]

Should the cognitect.transit namespace include functions that call through to the type constructor helpers in cognitect.transit.TransitFactory, as the ClojureScript implementation does (cf. https://github.com/cognitect/transit-cljs/blob/master/src/cognitect/transit.cljs#L355)?

[puredanger]

You can call through to the TransitFactory helpers in transit-java for these right now, but might be useful to also have Clojure wrappers for those. http://cognitect.github.io/transit-java/com/cognitect/transit/TransitFactory.html