Implement basic sygus, only possible in --manual mode for now

build.sbt

src/main/scala/leon/solvers/RawArray.scala

...ain/scala/leon/solvers/smtlib/SMTLIBCVC4ProofSolver.scala

...cala/leon/solvers/smtlib/SMTLIBCVC4QuantifiedSolver.scala

...cala/leon/solvers/smtlib/SMTLIBCVC4QuantifiedTarget.scala

src/main/scala/leon/solvers/smtlib/SMTLIBCVC4Solver.scala

src/main/scala/leon/solvers/smtlib/SMTLIBCVC4Target.scala

...in/scala/leon/solvers/smtlib/SMTLIBQuantifiedSolver.scala

...in/scala/leon/solvers/smtlib/SMTLIBQuantifiedTarget.scala

src/main/scala/leon/solvers/smtlib/SMTLIBSolver.scala

src/main/scala/leon/solvers/smtlib/SMTLIBTarget.scala

...in/scala/leon/solvers/smtlib/SMTLIBUnsupportedError.scala

.../scala/leon/solvers/smtlib/SMTLIBZ3QuantifiedSolver.scala

.../scala/leon/solvers/smtlib/SMTLIBZ3QuantifiedTarget.scala

src/main/scala/leon/solvers/smtlib/SMTLIBZ3Solver.scala

src/main/scala/leon/solvers/smtlib/SMTLIBZ3Target.scala

src/main/scala/leon/solvers/sygus/CVC4SygusSolver.scala

src/main/scala/leon/solvers/sygus/SygusSolver.scala

src/main/scala/leon/synthesis/Rules.scala

src/main/scala/leon/synthesis/Solution.scala