Renamed @FirstClass to @Functor
Changed nullsafe to graceful and added support for nullTo
Added javadocs
Update README.md
NullTo now implies graceful
Merge branch 'feature/graceful' into develop

* feature/graceful:
  NullTo now implies graceful
  Update README.md
  Added javadocs
  Changed nullsafe to graceful and added support for nullTo
  Renamed @FirstClass to @Functor