Smart insert and delete, continuous spell checking and autoscroll
        can now be used for any WebView, not just editable ones. All of
        these make sense for documents that might contain content editable 
        areas or our new text fields. Autoscroll is usefull for dragging
        for file input controls also.

        Added a SPI to toggle WebViews tab key behavior, tabKeyCyclesThroughElements.
        WebHTMLView's _interceptEditingKeyEvent now uses WebView's
        tabKeyCyclesThroughElements state to determine whether or not
        to process tab key events. The idea here is that tabKeyCyclesThroughElements
        will be YES when this WebView is being used in a browser, and we
        desire the behavior where tab moves to the next element in tab order.
        If tabKeyCyclesThroughElements is NO, it is likely that the WebView
        is being embedded as the whole view, as in Mail, and tabs should input
        tabs as expected in a text editor. Using Option-Tab always cycles
        through elements.

        * WebView/WebHTMLRepresentation.m:
        (-[WebHTMLRepresentation finishedLoadingWithDataSource:]):
        * WebView/WebHTMLView.m:
        (-[NSArray _interceptEditingKeyEvent:]):
        * WebView/WebView.m:
        (-[WebViewPrivate init]):
        (-[WebView _autoscrollForDraggingInfo:timeDelta:]):
        (-[WebView _shouldAutoscrollForDraggingInfo:]):
        (-[WebView validateUserInterfaceItem:]):
        (-[WebView toggleSmartInsertDelete:]):
        (-[WebView toggleContinuousSpellChecking:]):
        (-[WebView setTabKeyCyclesThroughElements:]):
        (-[WebView tabKeyCyclesThroughElements]):
        * WebView/WebViewPrivate.h:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@15093 268f45cc-cd09-0410-ab3c-d52691b4dbfc