Add answer/hint for Chapter 2, Exercise 3
Remove and reorder excercises to match final version of the book.
Merge pull request #318 from Jazzatola/answerfix

Add answer/hint for Chapter 2, Exercise 3
Remove editorial comment
Merge remote-tracking branch 'upstream/master'

Conflicts:
	exercises/src/main/scala/fpinscala/gettingstarted/GettingStarted.scala