scala/scala 10 pull requests

• [#10919] Deprecate Map.{filterKeys,mapValues} while undeprecating those in MapView Aug 9
• Override some collections methods in Range to use optimised implementations Aug 13
• Fix transitive equality on VectorMap Aug 15
• use AbstractIterator in VectorMap Aug 17
• Improve VectorMap equals performance Aug 20
• Avoid Some boxing in HashMap.apply Aug 20
• Changing s.c.i.Vector.iterator to return Iterator.empty on empty Aug 21
• Making VectorIterator a final class Aug 21
• use Iterable.single instead of Some(_). remove intermediate objects Aug 24
• remove collection.concurrent.RestartException Aug 24