added logging of target error codes to enable automatic error handling from tcl.
the plan is to use a computer to execute a series of tcl commands, the changes allow simple parsing of return messages to detect errors.
Change-Id: Ia98d3bd036e1b6065b475ffff6c1d30baeaf7417 Signed-off-by: Rodrigo L. Rosa <rodrigorosa.lg@gmail.com>
Reviewed-on: http://openocd.zylin.com/215 Tested-by: jenkins Tested-by: Øyvind Harboe <oyvindharboe@gmail.com> Reviewed-by: Øyvind Harboe <oyvindharboe@gmail.com>