rvinterf backslash escape: introduce libprint The new helper function library named libprint is meant to replace the badly misnamed libg23, and will soon contain functions for printing all of the same kinds of GPF TST packets that are now handled in libg23. However, we are also moving safe_print_trace() from libasync to this new library, and changing it to emit our new backslash escape format.

#define	ERROR_USAGE	1
#define	ERROR_TARGET	2
#define	ERROR_RVINTERF	3
#define	ERROR_UNIX	4
#define	ERROR_BUG	5
/* the following two are for fc-rfcal-tools */
#define	ERROR_RFTEST	6	/* error in the external RF test equipment */
#define	ERROR_RFFAIL	7	/* RF calibration process failure */