implement the iOS-like switch for the graph options
generalize OnOffSwitch and ChoiceSwitch
move test
doc
update
move graph switch to SolutionsGraphNode
don't use PHMeter model element in 'Solutions' and 'Custom' screens
move PHMeter to basics.model
add swtich to 'Custom' graph
make meter scale a little wider
slider -> thumb
background -> track
y position
gray out unselected choice
add string params for labels, support any type of 'choice'
add enums for graph type and units