Added customHigh/Low for graph and Alarm

Substituted customHigh/Low for targetTop/Bottom. 
Alarm function still does not "take" the custom values... still rings at 180/80 only. 
Storage from browserSettings, this allows for multiple devices looking at same website to customize their levels. 
if set Server-Side then you can have continuity across all devices, but less flexibility if you have different monitors for Night/Day.