Added a test for all (xs) should not contain (value) syntax
Added tests for not (contain (value)) and (not contain value) for inspector shorthands.
Made a ListShouldContainSpec to try the NormalizingEquality test.
Added back in remaining two paren-placement test with not contain value in ListShouldContainSpec.
Got the NormalizingEquality test to work for List.
Added some commented out lines of code that don't compile, trying to get
a satisfying explicit syntax for Holders.
Changed Normalization's isInstanceOfA method to normalizedIfInstanceOfA.
Better, but still not terribly satisfying.