More timings

src/main/scala/leon/synthesis/CostModel.scala

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

src/main/scala/leon/synthesis/Synthesizer.scala

src/main/scala/leon/synthesis/graph/Search.scala

src/main/scala/leon/synthesis/rules/ADTSplit.scala

src/main/scala/leon/synthesis/rules/Cegis.scala

src/main/scala/leon/utils/Timer.scala