Raynos/reduce — pull request #7 by ljharb (2013-08-21 00:53:16+00:00)
Title: Argument length

This isn't a big deal obviously, but:
- Array#reduce is spec'd to have a length of 1
- a convention used in ES to indicate required versus optional arguments is that the function's length is the number of required args
- here, a length of 2 makes sense, since only the array and iterator are required

Thoughts?