<rdar://problem/4125131> REGRESSION (Mail): after certain steps,
        extra blank line appears when typing past end of reply-quoted text
        <rdar://problem/4024996> Applying block styles can cause assertion
        failure in inline style removal

        Prevent VisiblePositions at [br, 1] at the end of root editable elements.

        Layout tests added:
        * inserting/insert-at-end-01.html
        * inserting/insert-at-end-02.html

        Layout tests changed (fixed):
        * editing/deleting/delete-br-011.html
        * editing/deleting/delete-at-paragraph-boundaries-011.html
        * editing/inserting/insert-3786362-fix.html

        * khtml/editing/apply_style_command.cpp:
        (khtml::ApplyStyleCommand::applyInlineStyle):
        Do the layout before calculating start/end positions, not after,
        since upstream/downstream need to know who is rendered/unrendered.
        Don't do equivalentRangeCompliantPosition() on the start position
        in addition to downstream(), since it a) is confusing, b) frequently
        causes start/end to be equal, making removeInlineStyle a no-op and
        c) causes an assertion to fire.
        Only reset start/end using endingSelection() if splitTextElement was
        needed, since reseting start/end negates the work done above to swap
        start/end if they are backwards.
        When the start position points off the end of a node, that node should
        be skipped in all cases, not just the start.node() != end.node() case.

        * khtml/editing/composite_edit_command.cpp:
        (khtml::CompositeEditCommand::appendBlockPlaceholder):
        (khtml::CompositeEditCommand::insertBlockPlaceholder):
        Placeholders should be allowed in nodes that aren't blockFlow, for example,
        deleting the b in <div><span>b</span></div> should insert a placeholder.
        The assertion here should really be something like isBlockFlow ||
        isInlineFlow, but I can't assert those until deletion improves (4244964).

        * khtml/editing/delete_selection_command.cpp:
        (khtml::DeleteSelectionCommand::calculateTypingStyleAfterDelete):
        Don't try to select the placeholder when applying style to it.  It
        isn't necessary, and it's now impossible to do at the end of the
        document in any case.

        * khtml/editing/visible_position.cpp:
        (khtml::VisiblePosition::initDownstream):
        Don't create VisiblePositions at [br, 1] at the end of editable blocks, it
        produces strange/inconsistent editing behavior at the end of the document.

        * khtml/khtml_part.cpp: Fixed a comment.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@11086 268f45cc-cd09-0410-ab3c-d52691b4dbfc