Get touchstones that include this scenario

Given a particular touchstone and scenario, we can loookup all the other touchstones that also contain this scenario.

montagu_touchstones_for_scenario(modelling_group_id, touchstone_id,
  scenario_id, location = NULL)

Arguments

modelling_group_id	id of the modelling group. If omitted, or null, then all scenarios associated with the touchstone are returned.
touchstone_id	id of the touchstone (including version)
scenario_id	id of the scenario
location	The montagu server to connect to.

vector of touchstone ids