Add initial CommonCrypto bindings (no backend yet)
cover a missing branch in the commoncrypto bindings
add is_available() to CommonCrypto binding, use it for skipif
add CommonCrypto binding docs
refactor commoncrypto's is_available to check platform for now
Merge branch 'master' into common-crypto-binding

* master:
  temporary workaround for travis-ci bug
  Style nit
  easy_install is awful, don't use it
  Simplify the authors section
Merge pull request #405 from reaperhulk/common-crypto-binding

CommonCrypto Binding