TypeScript & Flow Definitions incomplete for partial application

[TylorS]

The functions zip, zipItems, snapshot, slice, scan, loop and combine all have invalid TypeScript definitions when using partial application. We'll want to use the same techniques describe in #288 to correct all our definitions.

[briancavalier]

The same seems to be true for flow defs. I think the same "tree" technique we chatted about will work for both TS and Flow.

[Frikki]

Added to the never-ending backlog.

[raveclassic]

TS part should be fixed in #296

[Frikki]

I guess we only need flow definitions then?