[PATCH] MI error messages

[Nick Roberts]

 > We have a syntax for error messages... let's use it?

Are you referring to the return value MI_CMD_ERROR?  Interestingly this isn't
used at all in mi-cmd-var.c or mi-cmd-stack.c but I think it is more
appropriate for the errors generated there.  It only goes back to
captured_mi_execute_command and doesn't generate any output in the log stream
(&"...").  I'm not too keen on procedures with lots of return points though.

Nick