[NTG-context] m-obsolete.tex has an undefined control sequence

Hi Hans, I guess it should be \writestatus\m!system{skipping obsolete module} but somehow the file in the latest beta reads \writestatus\m!systems{skipping obsolete module} I have to define this macro to \def\m!systems{\m!system} before loading the bib module so that I can keep the system untouched. -- Best Regards Chen