remove old C++ code for creating input datagrams

	modified:   src/bruce/bruce.test.cc
	modified:   src/bruce/client/bruce_client.h
	modified:   src/bruce/client/libbruce_client.cc
	modified:   src/bruce/client/status_codes.h
	modified:   src/bruce/input_dg/any_partition/v0/v0_input_dg.test.cc
	deleted:    src/bruce/input_dg/any_partition/v0/v0_input_dg_writer.cc
	deleted:    src/bruce/input_dg/any_partition/v0/v0_input_dg_writer.h
	modified:   src/bruce/input_dg/any_partition/v0/v0_write_dg.cc
	modified:   src/bruce/input_dg/any_partition/v0/v0_write_dg.h
	modified:   src/bruce/input_dg/any_partition/v0/v0_write_msg.c
	modified:   src/bruce/input_dg/any_partition/v0/v0_write_msg.h
	modified:   src/bruce/input_dg/partition_key/v0/v0_input_dg.test.cc
	deleted:    src/bruce/input_dg/partition_key/v0/v0_input_dg_writer.cc
	deleted:    src/bruce/input_dg/partition_key/v0/v0_input_dg_writer.h
	modified:   src/bruce/input_dg/partition_key/v0/v0_write_dg.cc
	modified:   src/bruce/input_dg/partition_key/v0/v0_write_dg.h
	modified:   src/bruce/input_dg/partition_key/v0/v0_write_msg.h
	modified:   src/bruce/input_thread.test.cc
	modified:   src/bruce/simple_client/simple_bruce_client.cc