Reviewed by John

    Reviewed by John

        * khtml/dom/dom_string.cpp:
        (DOM::DOMString::substring): Expose method already on DOMStrimgImpl.
        * khtml/dom/dom_string.h: Ditto.
        * khtml/editing/htmlediting.cpp:
        (khtml::CompositeEditCommand::rebalanceWhitespace): New helper to create and execute a
        RebalanceWhitespaceCommand instance.
        (khtml::DeleteSelectionCommand::doApply): Call rebalanceWhitespace() after running command.
        (khtml::InsertLineBreakCommand::doApply): Ditto.
        (khtml::InsertParagraphSeparatorCommand::doApply): Ditto.
        (khtml::InsertParagraphSeparatorInQuotedContentCommand::doApply): Ditto.
        (khtml::InsertTextCommand::input): Ditto.
        (khtml::RebalanceWhitespaceCommand::RebalanceWhitespaceCommand): New command.
        (khtml::RebalanceWhitespaceCommand::~RebalanceWhitespaceCommand): Ditto.
        (khtml::RebalanceWhitespaceCommand::doApply): Ditto.
        (khtml::RebalanceWhitespaceCommand::doUnapply): Ditto.
        (khtml::RebalanceWhitespaceCommand::preservesTypingStyle): Ditto.
        (khtml::ReplaceSelectionCommand::completeHTMLReplacement): Ditto.
        * khtml/editing/htmlediting.h: Ditto.
        (khtml::RebalanceWhitespaceCommand::): Ditto.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@8124 268f45cc-cd09-0410-ab3c-d52691b4dbfc