some cleaning up, and a now correct handling of singletons etc.

src/purescala/Reporter.scala

src/purescala/Z3Solver.scala

src/purescala/z3plugins/bapa/AST.scala

src/purescala/z3plugins/bapa/BAPATheory.scala

src/purescala/z3plugins/bapa/BapaToPaTranslator.scala

src/purescala/z3plugins/bapa/NormalForms.scala

src/purescala/z3plugins/bapa/PrettyPrinter.scala

src/purescala/z3plugins/bapa/VennRegions.scala

vmcai2011-testcases/CADE07.scala

vmcai2011-testcases/JustFormulas.scala

vmcai2011-testcases/Nasty.scala