Removing null in nextOrEndOfStream. Instead of a NullPointerException, we now get the friendly asserts

adding colinrgodsey to copyright waiver
Merge branch 'master' of https://github.com/reactive-streams/reactive-streams into nullfix-squash

Conflicts:
	CopyrightWaivers.txt
Merge pull request #169 from MediaMath/nullfix-squash

Removing null in nextOrEndOfStream on env flop