This shows how the builtin T,M6,M61,S,F codes can be redefined, optionally by referring 
to the builtin behaviour in the remap procedure.

The collection of prologs and epilogs in python-stdglue is intended to be a boilerplate
set of Python glue which covers most use cases. Normally you shouldnt need to touch any
of these.

The ngc remap routines in nc_subroutines have been set up to:

- show the 'exposed parameters' with a debug statement
- refer to the builtin codes within the remap procedure, such that execution effect is
  the same as not remapping that code (i.e. the remap result is idempotent)
- to work with the stdglue prologs and epilogs

'exposed parameters' are local variables in the remap procedure which can be read,
and changed - any changes will be picked up by the epilog and used to commit the result


Note that using M61 requires iocontrol-v2 as set tool number support in iocontrol is broken.