Remove legacy Ray code. (#3121)

* Remove legacy Ray code.

* Fix cmake and simplify monitor.

* Fix linting

* Updates

* Fix

* Implement some methods.

* Remove more plasma manager references.

* Fix

* Linting

* Fix

* Fix

* Make sure class IDs are strings.

* Some path fixes

* Fix

* Path fixes and update arrow

* Fixes.

* linting

* Fixes

* Java fixes

* Some java fixes

* TaskLanguage -> Language

* Minor

* Fix python test and remove unused method signature.

* Fix java tests

* Fix jenkins tests

* Remove commented out code.

python/ray/ray_constants.py

@@ -5,7 +5,7 @@ from __future__ import print_function
 
 import os
 
-from ray.local_scheduler import ObjectID
+from ray.raylet import ObjectID
 
 
 def env_integer(key, default):
@@ -41,7 +41,6 @@ REGISTER_ACTOR_PUSH_ERROR = "register_actor"
 WORKER_CRASH_PUSH_ERROR = "worker_crash"
 WORKER_DIED_PUSH_ERROR = "worker_died"
 PUT_RECONSTRUCTION_PUSH_ERROR = "put_reconstruction"
-HASH_MISMATCH_PUSH_ERROR = "object_hash_mismatch"
 INFEASIBLE_TASK_ERROR = "infeasible_task"
 REMOVED_NODE_ERROR = "node_removed"
 MONITOR_DIED_ERROR = "monitor_died"