Reviewed by Darin.
        
        <rdar://problem/5234383> REGRESSION: Sentence breaker method returning entire document length

        * editing/selection/5234383-1-expected.checksum: Added.
        * editing/selection/5234383-1-expected.png: Added.
        * editing/selection/5234383-1-expected.txt: Added.
        * editing/selection/5234383-1.html: Added.
        * editing/selection/5234383-2-expected.checksum: Added.
        * editing/selection/5234383-2-expected.png: Added.
        * editing/selection/5234383-2-expected.txt: Added.
        * editing/selection/5234383-2.html: Added.

WebCore:

        Reviewed by Darin.
        
        <rdar://problem/5234383> REGRESSION: Sentence breaker method returning entire document length
        
        The functions for moving the caret to the next/previous sentence boundary
        were in many cases moving to the beginning/end of the document.  The functions that 
        should move the caret to an equivalent position in the next/previous sentence behaved
        like the aforementioned functions ought to.  Put the code from the second two functions
        in the first and made sure that the second two are properly FIXMEd.  They're rarely 
        used (filed 5323691).
        
        * editing/SelectionController.cpp:
        (WebCore::SelectionController::modify): Added an option for sentenceBoundary granularity,
        so that we can test the functions that were broken from JS.
        * editing/visible_units.cpp:
        (WebCore::startOfSentence): Removed the FIXME about 5234383.
        (WebCore::endSentenceBoundary): Make this function do what nextSentencePositionBoundary
        current does.
        (WebCore::endOfSentence): Removed the FIXME about 5234383.
        (WebCore::previousSentencePosition): Removed an incorrect FIXME.
        (WebCore::nextSentencePositionBoundary): Tweaked FIXME.  This function is
        identical, not close to endSentenceBoundary.
        (WebCore::nextSentencePosition): Removed an incorrect FIXME.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@24187 268f45cc-cd09-0410-ab3c-d52691b4dbfc