Return the actual value from write operations

adaptors/java/src/se/lth/control/realtime/moberg/Moberg.java

adaptors/java/src/se_lth_control_realtime_moberg_Moberg.c

adaptors/julia/AnalogOut.jl

adaptors/julia/DigitalOut.jl

adaptors/matlab/analogout.c

adaptors/matlab/digitalout.c

adaptors/python/python-moberg.c

moberg.h

plugins/comedi/comedi.c

plugins/libtest/libtest.c

plugins/serial2002/serial2002.c

test/Makefile

test/test_io.c

test/test_jl.jl

test/test_start_stop.c