Added inductive sort test (and fixed small related bugs)

...cala/inox/solvers/unrolling/InductiveUnrollingSuite.scala

src/main/scala/inox/Reporter.scala

src/main/scala/inox/solvers/smtlib/CVC4Target.scala

src/main/scala/inox/solvers/smtlib/Z3Target.scala

src/main/scala/inox/solvers/z3/AbstractZ3Solver.scala