Implement scheduler over rides

This creates scheduler over-ride capabilities within the Irrigation Controller Device Type (adds new tile), replacing the need to install an the optional virtual scheduler device type.  

This gives the Irrigation Controller Smart Phone app  the ability to over-ride the Scheduler App.  Use cases include:
*Pause the scheduler app, for example during the winter months or during yard work
*Expedite and over-ride the rain delay feature on the scheduler app
*Skip 1X - skip one watering, for example if you notice that the lawn is wetter than desirable or if yard work is occurring at same time as an irrigation