Add RadioGroupViewElement impl
Revert #getSelectedOption
Remove RadioGroupViewElement for now, add HtmlElements for Radio and Checkbox
Add HtmlDateSelect, HtmlMultiSelect interfaces, update HtmlElements
Add HtmlDateInput interface, fix static imports and method names in HtmlElements
Fix static imports, add default implementations for HtmlMultiSelects and HtmlDateInputs
Merge remote-tracking branch 'dmcneil/i18-fundamental-ui-element-types'