Reviewed by Justin.

        <rdar://problem/5031181> cntl-k at end of paragraph adds nothing to the kill ring
        <rdar://problem/5031189> REGRESSION: cntl-y yanks only the most recently killed content

        * editing/pasteboard/emacs-ctrl-k-y-001-expected.checksum: Added.
        * editing/pasteboard/emacs-ctrl-k-y-001-expected.png: Added.
        * editing/pasteboard/emacs-ctrl-k-y-001-expected.txt: Added.
        * editing/pasteboard/emacs-ctrl-k-y-001.html: Added.

WebCore:

        Reviewed by Justin.

        <rdar://problem/5031181> cntl-k at end of paragraph adds nothing to the kill ring
        <rdar://problem/5031189> REGRESSION: cntl-y yanks only the most recently killed content

        For rdar://5031181, properly extend the selection before the killring handling, and
        make sure plainText of that selection returns a linefeed.
        
        For rdar://5031189, restore Editor::deleteRange() code that continued current killring,
        even though the range deletion implicitly stopped it via changing the selection.
        
        A byproduct of this change is the elimination of RUNDFINDER vs CONTENT TextIterator. The
        only difference between the two was whether to emit a newline when the range started
        with a blockflow element. No callers actually need that any more.

        Tests added:
        * editing/pasteboard/emacs-ctrl-k-y-001-expected.checksum: Added.
        * editing/pasteboard/emacs-ctrl-k-y-001-expected.png: Added.
        * editing/pasteboard/emacs-ctrl-k-y-001-expected.txt: Added.
        * editing/pasteboard/emacs-ctrl-k-y-001.html: Added.

        * editing/Editor.cpp:
        (WebCore::Editor::deleteRange):
        Clear the "start new kill ring sequence" setting, because it was set to true
        when the selection was updated by deleting the range.
        
        (WebCore::Editor::deleteWithDirection):
        If extending the selection to the end of paragraph resulted in a caret selection,
        extend by character, to handle the case when the selection started as a caret at
        the end of paragraph.
        
        * editing/TextIterator.cpp:
        (WebCore::TextIterator::TextIterator):
        Initialize new member variables for tracking handling of the beginning of the range.
        
        (WebCore::TextIterator::advance):
        Call representNodeOffsetZero on the m_endContainer.
        Move visibility checks into handleTextNode and handleReplacedElement.
        
        (WebCore::TextIterator::handleTextNode):
        (WebCore::TextIterator::handleTextBox):
        Call emitText.
        
        (WebCore::TextIterator::handleReplacedElement):
        Moved visibility check into here.
        
        (WebCore::shouldEmitNewlinesBeforeAndAfterNode):
        
        (WebCore::TextIterator::shouldRepresentNodeOffsetZero):
        (WebCore::TextIterator::representNodeOffsetZero):
        New. Emits proper sequence when encountering offset 0 of a node, including the
        m_endContainer. Started with code from handleNonTextNode.
        
        (WebCore::TextIterator::handleNonTextNode):
        Call representNodeOffsetZero.
        
        (WebCore::TextIterator::exitNode):
        Similar to shouldRepresentNodeOffsetZero, do not emit the newline if the node
        was collapsed, and before any other emitted content.
        
        (WebCore::TextIterator::emitCharacter):
        
        (WebCore::TextIterator::emitText):
        New. Consolidates code used by handleText and handleTextBox.
        
        (WebCore::CharacterIterator::CharacterIterator):
        Removed RUNFINDER.

        (WebCore::WordAwareIterator::WordAwareIterator):
        Removed RUNFINDER.
        
        (WebCore::WordAwareIterator::advance):
        Formatting.

        (WebCore::TextIterator::rangeLength):
        Formatting.
        
        * editing/TextIterator.h:
        Added member variables for tracking handling of the beginning of the range.
        Eliminated concept of RUNDFINDER vs CONTENT TextIterator.
        
        * editing/visible_units.cpp:
        (WebCore::nextBoundary):
        Eliminated concept of RUNDFINDER vs CONTENT TextIterator.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@20166 268f45cc-cd09-0410-ab3c-d52691b4dbfc