Generic data acquisition routine

[hbluhm]

The current Measurement Scripts (which are actually not scripts) are rather specific and seem to duplicate a lot of code. A more generic solution (enhancing do_nd, similar to smrun in special measure) would be easiert to maintain. This issue should be tackled when major modifications or significant new functionalities are to be implemented. A proposal for an interface can be found here (Internal document). Short of that, gathering frequently used code into helper function could also improve the situation.