Merge pull request #37 from rossh/master

#30 Used a matcher instead of if else statement
Add option Example
Merge branch 'master' of github.com:julien-truffaut/Monocle
Add Each instance for List
Add mapEq from scalaz
Fix map Equal definition
Add Index
Add Index for String
Move ListExample to test
Move HList example to unit test
Move GenericExample to unit test
Move safe cast example to unit test
Move Iso example to unit test
Move Lens example to unit test
Add filterIndexes
Refactor Index, FilterIndex and add At
Add missing changes
Move Each to function
Add Field 1 to 6 and remove tuple - use SimpleLens instead of Lens but they are more convenient to use
Add documentation