Cleaned up many old/useless options.

src/main/scala/leon/Logger.scala

src/main/scala/leon/Settings.scala

src/main/scala/leon/plugin/LeonPlugin.scala

src/main/scala/leon/purescala/Extractors.scala

src/main/scala/leon/solvers/z3/FairZ3Solver.scala

src/main/scala/leon/verification/AnalysisPhase.scala

src/main/scala/leon/verification/InductionTactic.scala