Style fixes

src/main/scala/leon/LeonOption.scala

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

src/main/scala/leon/purescala/Expressions.scala

src/main/scala/leon/synthesis/SynthesisContext.scala

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

src/test/scala/leon/test/synthesis/SynthesisSuite.scala