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
Merge pull request #41 from aik099/incorrect-mink-method-usage-in-elements-fix

Fix incorrect NodeElement usages in Typified Elements