OptionSelectable interface for CheckboxGroup
OptionSelectableGroup common implementation Checkbox and RadioGroup
all hell broke loose with OptionSelectable page object

SelectList wraps select watir and not delegate to it.
SelectList, RadioGroup, CheckboxGroup should have the same interface.
wip on this.
wip value and options
OptionSelectable.value unified interface to query for value

SelectList, CheckboxGroup, RadioGroup should have the same
way of asking for value.
By default they return the default way of array of strings
or you can qualify asking for value with keys that
correspond to option keys
OptionSelectable interface to value and options methods
OptionSelectable interface spec complete
feature 'option_selectable' Select, RadioGroup, CheckboxGroup

SelectList, CheckboxGroup, RadioGroup
act like OptionSelectable PageObject
Single Select acts like RadioGroup
Mulit Select acts like CheckboxGroup