* Ray doc - changed python indentation to 4 spaces in documentation files actors.rst, api.rst, and example-*.rst
* Ray documentation - changed Python to 4 space indentation for files install-*.rst, installation-troubleshooting.rst, internals-overview.rst, serialization.rst, troubleshootin.rst, tutorial.rst, using-ray-*.rst
* Rewrote and reordered the examples in the Actor documentation for clarity. Also added an introduction to Gym
* Minor tweaks to actor documentation
* Small changes to wording.
* Perform ray.register_class under the hood.
* Fix bug.
* Release worker lock when waiting for imports to arrive in get.
* Remove calls to register_class from examples and tests.
* Clear serialization state between tests.
* Fix bug and add test for multiple custom classes with same name.
* Fix failure test.
* Fix linting and cleanups to python code.
* Fixes to documentation.
* Implement recursion depth for recursively registering classes.
* Fix linting.
* Push warning to user if waiting for class for too long.
* Fix typos.
* Don't export FunctionToRun if pickling the function fails.
* Don't broadcast class definition when pickling class.
* Direction substitution of @ray.remote -> @ray.task.
* Changes to make '@ray.task' work.
* Instantiate actors with Class.remote() instead of Class().
* Convert actor instantiation in tests and examples from Class() to Class.remote().
* Change actor method invocation from object.method() to object.method.remote().
* Update tests and examples to invoke actor methods with .remote().
* Fix bugs in jenkins tests.
* Fix example applications.
* Change @ray.task back to @ray.remote.
* Changes to make @ray.actor -> @ray.remote work.
* Direct substitution of @ray.actor -> @ray.remote.
* Fixes.
* Raise exception if @ray.actor decorator is used.
* Simplify ActorMethod class.
