Add preliminary GRPC server for PyBullet and BulletRobotics.

Will add GRPC client and PyBullet GRPC server plugin.
Will cover most/all SharedMemoryCommand/SharedMemoryStatus messages.
Run the server, then test using the pybullet_client.py

examples/SharedMemory/grpc/pybullet_pb2_grpc.py

@@ -0,0 +1,46 @@
+# Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
+import grpc
+
+import pybullet_pb2 as pybullet__pb2
+
+
+class PyBulletAPIStub(object):
+  # missing associated documentation comment in .proto file
+  pass
+
+  def __init__(self, channel):
+    """Constructor.
+
+    Args:
+      channel: A grpc.Channel.
+    """
+    self.SubmitCommand = channel.unary_unary(
+        '/pybullet_grpc.PyBulletAPI/SubmitCommand',
+        request_serializer=pybullet__pb2.PyBulletCommand.SerializeToString,
+        response_deserializer=pybullet__pb2.PyBulletStatus.FromString,
+        )
+
+
+class PyBulletAPIServicer(object):
+  # missing associated documentation comment in .proto file
+  pass
+
+  def SubmitCommand(self, request, context):
+    """Sends a greeting
+    """
+    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+    context.set_details('Method not implemented!')
+    raise NotImplementedError('Method not implemented!')
+
+
+def add_PyBulletAPIServicer_to_server(servicer, server):
+  rpc_method_handlers = {
+      'SubmitCommand': grpc.unary_unary_rpc_method_handler(
+          servicer.SubmitCommand,
+          request_deserializer=pybullet__pb2.PyBulletCommand.FromString,
+          response_serializer=pybullet__pb2.PyBulletStatus.SerializeToString,
+      ),
+  }
+  generic_handler = grpc.method_handlers_generic_handler(
+      'pybullet_grpc.PyBulletAPI', rpc_method_handlers)
+  server.add_generic_rpc_handlers((generic_handler,))