* Small cleanups in worker.py.
* Remove dependencies on subprocess32, graphviz, protobuf, and ipython.
* Retry starting the plasma manager if the port is in use.
* Whitespace
* Move start_plasma_manager into plasma.py.
* Update worker code and services code to use plasma and the local scheduler.
* Cleanups.
* Fix bug in which threads were started before the worker mode was set. This caused remote functions to be defined on workers before the worker knew it was in WORKER_MODE.
* Fix bug in install-dependencies.sh.
* Lengthen timeout in failure_test.py.
* Cleanups.
* Cleanup services.start_ray_local.
* Clean up random name generation.
* Cleanups.
