Started with scalactic Equivalence; === doesn't work; WIP
Merge branch 'master' into bugfix/denotation-eq

Conflicts:
	src/main/scala/cosas/Denotation.scala
	src/test/scala/cosas/WrapTests.scala
Working strict scalaz equality mixed in tests
clean imports a bit
another check, minor edits
Merge branch 'bugfix/denotation-eq'