Fix for this bug:

	Radar 3132171 (trying to login at mypage.apple.com gives "Already Connected" message)

	The issue is that we submit the login form more than once when the user hits
	the return key to submit rather than clicking the submit button. We are also
	susceptible to double form submissions from buggy scripts that ask to submit
	more than one form.

	The fix is to prevent the KWQKHTMLPart from submitting more than one form by
	setting and checking a flag.

        * kwq/KWQKHTMLPart.h: Add a form submit flag.
        * kwq/KWQKHTMLPart.mm:
        (KWQKHTMLPart::submitForm): Check form submit flag. Return if a form
	has already been submitted.
        (KWQKHTMLPart::setView): Reset form flag. This is done since the part
	may have been retrieved for reuse from the bac/forward cache.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@3153 268f45cc-cd09-0410-ab3c-d52691b4dbfc