Make axes which contribute to "in-motion" state configurable

As a support person, I want to be able to configure which axes contribute to the "in-motion" state of an instrument, so that some items of equipment can be made to move without causing the waitformove() method to wait unnecessarily (or even indefinitely).
#### Acceptance Criteria
1. As a support person, I can indicate which motion devices contribute to the "in-motion" state.
2. Only devices which are marked as "in-motion" contributors can trigger the "in-motion" state.
#### Notes
1. A typical use case for this story is the need to have a continuously rotating device (e.g. a motor to rotate a sample). If the continuously rotating device contributes to the "in-motion" state, then waitformove() methods will wait indefinitely and it will not be possible to control the instrument. Clearly, this is undesirable.
2. Probably best to manage as an exception list.
3. Does it need a GUI change (e.g. add a check-box to one of the drill-down motor screens).
4. Ask what scientists think of providing a list of things to wait for in a "waitformove".