Merge synthesis/repair fixes/new features

build.sbt

src/main/scala/leon/LeonContext.scala

src/main/scala/leon/codegen/CompilationUnit.scala

src/main/scala/leon/codegen/runtime/Monitor.scala

src/main/scala/leon/datagen/VanuatooDataGen.scala

src/main/scala/leon/evaluators/AngelicEvaluator.scala

src/main/scala/leon/evaluators/CodeGenEvaluator.scala

src/main/scala/leon/evaluators/DefaultEvaluator.scala

src/main/scala/leon/evaluators/DualEvaluator.scala

src/main/scala/leon/evaluators/Evaluator.scala

src/main/scala/leon/evaluators/RecursiveEvaluator.scala

...scala/leon/invariant/engine/UnfoldingTemplateSolver.scala

...in/scala/leon/invariant/templateSolvers/CegisSolver.scala

...ala/leon/invariant/templateSolvers/ExtendedUFSolver.scala

...la/leon/invariant/templateSolvers/FarkasLemmaSolver.scala

...riant/templateSolvers/UniversalQuantificationSolver.scala

src/main/scala/leon/invariant/util/Minimizer.scala

src/main/scala/leon/invariant/util/SolverUtil.scala

src/main/scala/leon/purescala/ExprOps.scala

src/main/scala/leon/purescala/SelfPrettyPrinter.scala