Update README.md
Updated answers and code after major revisions throughout
Merge remote-tracking branch 'origin/master'
updated readmes
Merge remote-tracking branch 'upstream/master'

Conflicts:
	exercises/src/main/scala/fpinscala/datastructures/List.scala
	exercises/src/main/scala/fpinscala/errorhandling/Either.scala
	exercises/src/main/scala/fpinscala/errorhandling/Option.scala
	exercises/src/main/scala/fpinscala/laziness/Stream.scala
	exercises/src/main/scala/fpinscala/state/State.scala
merged with the upstream