changed names of table headers to better match those in papers
added true and false predicates to the alloy specifications that we generate
added support for the 'no change' expression
Changed oracle to use the syntactic evaluator. This fixes two major problems:

1. The test is now correct, as it uses the concrete values from the sut and not those of
an existential quantifier (which may be unrelated to the values given by the sut)
2. It prevents eliminates the higher-order quantification problem.
added the product-line demo