[HtmlUnit] HtmlRadioButtonInput

[<Mik...@su...>]

It appears that javascript support for the onlick event handler of an input
element of type "radio" has not been implemented in the latest CVS sources.
Assuming this is correct, I propose to add a click method to
com.gargoylesoftware.htmlunit.html.HtmlRadioButtonInput that is similar to the
click method on com.gargoylesoftware.htmlunit.html.HtmlAnchor.  Is this the
correct path to take?

Mike