Simplify zip and merge apis to a single variant each
Simplify takeUtil
Further simplify takeUntil
Ensure takeUntil only asks for first signal step
Merge pull request #37 from cujojs/simplify-zip-merge

Simplify zip and merge apis to a single variant each
Reduce closure size
Add initial API docs.

Includes TOC and docs for creating and building streams.  Still much
more to write.
Add more API docs.

Revise API doc format to accomodate method + function versions of
combinators
Add initial merge docs
Add Element.matches event delegation example
Add merge and zip docs
Add transform and filter docs
Add more filtering docs
Add reduce docs