[Therion] backcompass and backclino in team and instrument descriptions

[Duncan Collis]

Hi,

I think I may have found a minor bug:

Therion does not accept 'backcompass' or 'backclino' as a valid role
in the team command or a valid description in the instrument command

eg this does not work:

team "Fred Flintstone" tape backcompass backclino
instrument backcompass "Silva Type80 F"
instrument backclino "Suunto 646575"

whereas this is OK:

team "Barney Rubble" notes compass clino
instrument compass "Silva Type80 C"
instrument clino "Suunto 522534"

The equivalent role and description are valid for the *team and
*instrument commands in Survex.

Duncan Collis