declarative methods for red-black trees and lists, verbosity parameter

cp-demo/executing-specs/IntSqrt.scala

cp-demo/executing-specs/ListMethods.scala

cp-demo/executing-specs/RedBlackTreeMethods.scala

src/cp/CPPlugin.scala

src/cp/RuntimeSettings.scala

src/cp/Terms.scala

src/purescala/FairZ3Solver.scala