Clean only text fields before setting a value

Hi,

setValue method clears the current value before setting the new one, but according to selenium2 docs (http://code.google.com/p/selenium/wiki/JsonWireProtocol#/session/:sessionId/element/:id/clear) only textarea and text elements can be cleared.

With the current implementation fillField (called from steps definitions like "I fill in the following:") also sends select fields through clear() this should not be a problem (Has no effect on other elements -> http://selenium.googlecode.com/svn/trunk/docs/api/java/org/openqa/selenium/WebElement.html#clear() ) but it does since I'm receiving a "Element must be user-editable in order to clear it.".

I've executed the MinkSelenium2Driver unit tests getting the same non-related failures before and after applying this patch.