Added a decorated page object that allows interaction with a radio or checkbox groups labels. It allows a user to select by text instead of element attribute values
Merge proposed 'labeled_group' from jmcintyre.
refactor. let LabelledGroup wrap the actual Group pageobject
refactor. how about we set individual radios or checkboxes from positions of labels in array.
refactor. how about for value find all element.set? in a group and return corresponding labels text
refactor. use Labels object for labels construction
turn LabelledGroup into Delegator for transparent CheckboxGroup or RadioGroup access
to_labeled allows conversion of CheckboxGroup and CheckboxGroup to LabeledGroup
refactor. LabeledGroup as core component

allow RadioGroup and CheckboxGroup to be easily interacted with
as LabeledGroup using to_labeled conversion.
RadioGroup is not wrapped but delegated to so we have transparency
LabelMapper helps map collection of elements
to collection of corresponding labels for those elements.
merge 'labeled_group' feature
implement LabeledGroup.options returns array of label texts