add popl revision notes

popl19/decision.md

+Decision comment: the consensus of the reviewers is to accept the
+paper. The reviewers appreciate the principled approach to designing
+gradual type systems, and the extension of gradual typing to CBPV. In
+the second round, the reviewers require the following changes:
+
+Specific changes:
+
+    More clearly situate where the work applies -- ie what
+	kinds of gradual systems this approach can work for.
+	
+    Clarify the relationship to AGT (Garcia et al), Henglein's
+	work on coercions, and Degen and Thiemann's work on contracts
+	for lazy languages.
+
+    Provide an example or discussion of how the main theorem
+	applies.
+
+More broadly:
+
+    Revise the paper to make the specific claims clearer and
+	avoid "story of discovery".
+
+    Please name the rules.