Wrong url in "HtmlElementsLive" test suite
Updating SelectOption/Radio element description to indicate correct usage
Changes to RadioGroup element

1. adding "getValue" method to Radio typified element that RadioGroup returns
2. replacing "check" (Mink method) usage with "selectOption"
3. updating tests to reflect code changes
4. adding tests to HtmlElementsLive test suite to assert radio button checking
Updating fixture to catch cases when radio/checkbox are not within same element