Update Device_Type_8_Zone_Irrigation_Controller.groovy

Implements the scheduler over-ride features found in the optional virtual scheduler app.  This replaces the need to use the virtual scheduler app.  

Key features include:
* "Pause" the system to turn it off for a period of time, for example over the winter or during extensive lawn work
* "Skip 1X" to skip one watering and then resume the normal schedule
* "Expedite" to water even if the virtual rain gauge  exceeds the threshold value
Update IrrigationSchedulerApp.groovy

Removes the option to select an optional virtual Irrigation scheduler accessory app and instead looks for scheduler over ride states from the associated device type.  Acceptable over-rides are 
"noEffect"
 "skip" - the scheduler will 1) skip a watering and 2) reset the "effect" value in the device type to "noEffect".   
"onHold"
"expedite"
Update Device_Type_24_Zone_Irrigation_Controller.groovy

Implements the scheduler over-ride features found in the optional virtual scheduler app.  This replaces the need to use the virtual scheduler app.  

Key features include:
* "Pause" the system to turn off the programmed schedules for a period of time, for example over the winter or during extensive lawn work
* "Skip 1X" to skip one watering and then resume the normal schedule
* "Expedite" to water even if the virtual rain gauge  exceeds the threshold value
Merge pull request #24 from d8adrvn/Implement_Scheduler_Over_Rides

Implement scheduler over rides