Add the @Lenses macro annotation

Fixes #18

Please note:
* add paradise compiler plugin for 2.11+, as it's need for annotations
* unfortunately it seems like annotation users need to add the paradise
  plugin too :( see http://stackoverflow.com/q/23485426/463761
* Bumped paradise/quasiquotes to 2.0.1
* Fails with a slightly obscure message when annotating a non-case class
* Slightly verbose, especially the quasiquote unlift of classDef..
* I eliminated the boilerplate in the test, instead of adding more tests
* I'm happy to redo anything, names, split commits, tests, etc..