Add `parallel` & `defers` docs and cleanup.
Merge pull request #14 from ssafejava/docs

Add `parallel` & `defers` docs.
Adding contributors.
Fix typo.
Merge pull request #15 from ssafejava/docs

Fix typo in docs.
Adding return result from fiber.
Add defer with timeout.
Fixing bugs.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	test/sync.js