Collapses 2.13 and 2.14 into one and changes the wording of the rule to be positive.
Rewords 1.8 so that it is simpler and positively worded.
Reformulates 1.9 in the same wording as 2.13.
Merge pull request #117 from reactive-streams/wip-106-√

Collapses 2.13 and 2.14 into one and changes the wording of the rule to ...