Merge branch 'master' of laragit.epfl.ch:projects/leon-2.0

src/main/scala/leon/purescala/TreeOps.scala

src/main/scala/leon/purescala/TypeTrees.scala

src/main/scala/leon/synthesis/Complexity.scala

src/main/scala/leon/synthesis/Heuristics.scala

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

src/main/scala/leon/synthesis/Solution.scala

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

src/main/scala/leon/synthesis/Task.scala

testcases/synthesis/Injection.scala

testcases/synthesis/SimplestCegis.scala