Fix wrong condition.
Use a HashMap and a little reflection to support any number of attributes.
Rename addAttribute to putAttribute to signify updatability.
Fix SimilarityTest.
Fix UtilsTest: use new put and get methods.
Move actual critiquing to Attribute itself.
Merge branch 'more-generic-attributes'
Correct likeValue description.
Make likeValue() and dislikeValue() overridable.