Twoway stacking example added.

examples/Makefile

examples/twoway/Makefile

examples/twoway/client.c

examples/twoway/decimating.c

examples/twoway/decimating.h

examples/twoway/decimating_messages.lc

examples/twoway/server.c

examples/twoway/types.lc

lib/c/Makefile

lib/c/labcomm.c

lib/c/labcomm.h

lib/c/labcomm_dynamic_buffer_writer.c

lib/c/labcomm_fd_reader.c

lib/c/labcomm_fd_writer.c

lib/c/labcomm_private.h

lib/c/test/test_labcomm_generated_encoding.c

test/Makefile