move bruce/util/field_access.h to base/field_access.h

	new file:   src/base/field_access.h
	modified:   src/bruce/bruce.test.cc
	modified:   src/bruce/input_dg/any_partition/v0/v0_input_dg_reader.cc
	modified:   src/bruce/input_dg/any_partition/v0/v0_input_dg_writer.cc
	modified:   src/bruce/input_dg/input_dg_util.cc
	modified:   src/bruce/input_dg/old_v0_input_dg_reader.cc
	modified:   src/bruce/input_dg/old_v0_input_dg_writer.cc
	modified:   src/bruce/input_dg/partition_key/v0/v0_input_dg_reader.cc
	modified:   src/bruce/input_dg/partition_key/v0/v0_input_dg_writer.cc
	modified:   src/bruce/input_thread.test.cc
	modified:   src/bruce/kafka_proto/v0/metadata_request_reader.cc
	modified:   src/bruce/kafka_proto/v0/metadata_request_reader.h
	modified:   src/bruce/kafka_proto/v0/metadata_request_writer.cc
	modified:   src/bruce/kafka_proto/v0/metadata_response_reader.cc
	modified:   src/bruce/kafka_proto/v0/metadata_response_writer.cc
	modified:   src/bruce/kafka_proto/v0/msg_set_reader.cc
	modified:   src/bruce/kafka_proto/v0/msg_set_writer.cc
	modified:   src/bruce/kafka_proto/v0/msg_set_writer.h
	modified:   src/bruce/kafka_proto/v0/produce_request_reader.cc
	modified:   src/bruce/kafka_proto/v0/produce_request_writer.h
	modified:   src/bruce/kafka_proto/v0/produce_response_reader.cc
	modified:   src/bruce/kafka_proto/v0/produce_response_writer.cc
	modified:   src/bruce/kafka_proto/v0/protocol_util.cc
	modified:   src/bruce/mock_kafka_server/cmd_worker.cc
	modified:   src/bruce/mock_kafka_server/serialize_cmd.cc
	modified:   src/bruce/mock_kafka_server/serialize_cmd.h
	modified:   src/bruce/mock_kafka_server/single_client_handler_base.cc
	modified:   src/bruce/mock_kafka_server/v0_client_handler.cc
	modified:   src/bruce/simple_client/simple_bruce_client.cc
	deleted:    src/bruce/util/field_access.h