Apply BSD 2 clauses license

src/main/scala/leon/TypeChecking.scala

src/main/scala/leon/UnitElimination.scala

src/main/scala/leon/codegen/CodeGenPhase.scala

src/main/scala/leon/codegen/CodeGeneration.scala

src/main/scala/leon/codegen/CompilationEnvironment.scala

src/main/scala/leon/codegen/CompilationException.scala

src/main/scala/leon/codegen/CompilationResult.scala

src/main/scala/leon/codegen/CompilationUnit.scala

src/main/scala/leon/codegen/CompiledExpression.scala

src/main/scala/leon/evaluators/CodeGenEvaluator.scala

src/main/scala/leon/evaluators/DefaultEvaluator.scala

src/main/scala/leon/evaluators/EvaluationResults.scala

src/main/scala/leon/evaluators/Evaluator.scala

src/main/scala/leon/plugin/AnalysisComponent.scala

src/main/scala/leon/plugin/CodeExtraction.scala

src/main/scala/leon/plugin/ExtractionPhase.scala

src/main/scala/leon/plugin/Extractors.scala

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

src/main/scala/leon/plugin/SimpleReporter.scala

src/main/scala/leon/plugin/TemporaryInputPhase.scala