maxDeepOffset is confusing and should be removed
        https://bugs.webkit.org/show_bug.cgi?id=24586

        Abstract some hard-to-read (but shared) logic into a new renderedAsNonInlineTableOrHR function.
        Add first/lastDeepEditingPositionForNode Position creation functions
        and deploy them to places we used to call maxDeepOffset.

        Rename Position::atStart and atEnd to atStartOfTree atEndOfTree
        Add a new Position::atFirst/atLastEditingPositionForNode() and use these
        to replace a few more callers for maxDeepOffset()

        Rename maxDeepOffset to lastEditingOffsetForNode (so that we mere mortals have some clue what it does)

        "Editing positions" are confusing because they have one
        of two behaviors, depending on if the container node is ignored
        by editing (if editingIgnoresContent(node) returns true) or not.
        Positions referring to nodes ignored by editing are
        neighbor-relative (they are before or after the node) where as
        positions reffering to other nodes are container-relative
        (they are between two child nodes of the container, identified
        by the offset() member).  I will be fixing this confusion in
        future patches.  These renames hopefully make the current behavior clearer.

        * dom/Position.cpp:
        (WebCore::Position::previous):
        (WebCore::Position::next):
        (WebCore::Position::atFirstEditingPositionForNode):
        (WebCore::Position::atLastEditingPositionForNode):
        (WebCore::Position::atStartOfTree):
        (WebCore::Position::atEndOfTree):
        (WebCore::Position::previousCharacterPosition):
        (WebCore::Position::nextCharacterPosition):
        (WebCore::Position::upstream):
        (WebCore::Position::isCandidate):
        (WebCore::firstDeepEditingPositionForNode):
        (WebCore::lastDeepEditingPositionForNode):
        * dom/Position.h:
        * dom/PositionIterator.cpp:
        (WebCore::PositionIterator::operator Position):
        (WebCore::PositionIterator::increment):
        (WebCore::PositionIterator::decrement):
        (WebCore::PositionIterator::atEnd):
        (WebCore::PositionIterator::atEndOfNode):
        * editing/CompositeEditCommand.cpp:
        (WebCore::CompositeEditCommand::positionAvoidingSpecialElementBoundary):
        * editing/DeleteSelectionCommand.cpp:
        (WebCore::isTableCellEmpty):
        (WebCore::DeleteSelectionCommand::removeNode):
        (WebCore::DeleteSelectionCommand::handleGeneralDelete):
        * editing/Editor.cpp:
        (WebCore::Editor::advanceToNextMisspelling):
        * editing/InsertLineBreakCommand.cpp:
        (WebCore::InsertLineBreakCommand::doApply):
        * editing/InsertListCommand.cpp:
        (WebCore::InsertListCommand::doApply):
        * editing/ReplaceSelectionCommand.cpp:
        (WebCore::ReplaceSelectionCommand::positionAtEndOfInsertedContent):
        * editing/TypingCommand.cpp:
        (WebCore::TypingCommand::forwardDeleteKeyPressed):
        * editing/VisiblePosition.cpp:
        (WebCore::VisiblePosition::previous):
        (WebCore::VisiblePosition::leftVisuallyDistinctCandidate):
        (WebCore::VisiblePosition::left):
        (WebCore::VisiblePosition::rightVisuallyDistinctCandidate):
        (WebCore::VisiblePosition::right):
        * editing/VisibleSelection.cpp:
        (WebCore::VisibleSelection::selectionFromContentsOfNode):
        (WebCore::VisibleSelection::adjustSelectionToAvoidCrossingEditingBoundaries):
        * editing/htmlediting.cpp:
        (WebCore::nextVisuallyDistinctCandidate):
        (WebCore::previousVisuallyDistinctCandidate):
        (WebCore::firstEditablePositionAfterPositionInRoot):
        (WebCore::lastEditablePositionBeforePositionInRoot):
        (WebCore::lastOffsetForEditing):
        (WebCore::isFirstPositionAfterTable):
        (WebCore::isLastPositionBeforeTable):
        (WebCore::positionBeforeNode):
        (WebCore::positionAfterNode):
        (WebCore::enclosingEmptyListItem):
        (WebCore::caretMaxOffset):
        * editing/htmlediting.h:
        * editing/visible_units.cpp:
        (WebCore::renderedAsNonInlineTableOrHR):
        (WebCore::startOfParagraph):
        (WebCore::endOfParagraph):
        (WebCore::startOfEditableContent):
        (WebCore::endOfEditableContent):
        * page/AccessibilityObject.cpp:
        (WebCore::endOfStyleRange):
        * page/AccessibilityRenderObject.cpp:
        (WebCore::AccessibilityRenderObject::visiblePositionRange):
        * rendering/RenderBox.cpp:
        (WebCore::RenderBox::positionForPoint):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@41863 268f45cc-cd09-0410-ab3c-d52691b4dbfc