ACTION 295 - proposed implementation in the wiki

Dear all,

Wiki page
https://www.w3.org/2015/spatial/wiki/Measurement_and_Operating_properties_for_actuators
now
contains a proposed implementation for option 2 where:

 - hasMeasurementCapability, MeasurementCapability, MeasurementProperty are
replaced by hasSystemCapability, SystemCapability, SystemProperty,
respectively.
 - the definition of each of the subclasses of the old MeasurementProperty
class is updated to reflect the fact that this property may also apply to
actuators.

I encourage experts in actuators to double check the proposed defintions.

Best,
Maxime