Added zipAll function for #140

 Added functionality for zipping of N streams and added tests.
The docs are markdown, so you don't need to use `<b>`.

As a matter of formatting, can you change it to be `_finite_` here to get `<em>` for emphasis. Also change the "N" to "`N`" and "(N + 1)th" to "`(N + 1)`-th".