nml-messages.txt update to reflect emc.hh
nml-messages.txt update to reflect emc.hh

This documentation file has not been updated recently (years) and included
numerous items like "Obs: not used ..." so this is a restart based on current
emc.hh

Not included:
  NMLTYPE number
  details

If someone wants to update details, this could be a start point, otherwise
it just lists current message items from the source: emc.hh

Signed-off-by: Dewey Garrett <546ec366615570e68497e3c5df9092106a9808f4@panix.com>

ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror