Reviewed by Maciej.

    Reviewed by Maciej.

        http://bugs.webkit.org/show_bug.cgi?id=14525
        Support exslt:node-set()

        Test: fast/xsl/exslt-node-set.xml

        * xml/XSLTExtensions.cpp: Added.
        (WebCore::exsltNodeSetFunction): A copy of exslt:node-set() implementation
        from libexslt 1.1.11 (shipped with Tiger).
        (WebCore::registerXSLTExtensions): This function registers any WebCore-provided
        extensions on a context. Currently, the only extension is exslt:node-set().
        * xml/XSLTExtensions.h: Added.

        * xml/XSLTProcessor.cpp:
        (WebCore::XSLTProcessor::transformToString):
        Register extensions when creating a context.

        * WebCore.pro:
        * WebCore.vcproj/WebCore.vcproj:
        * WebCore.xcodeproj/project.pbxproj:
        * WebCoreSources.bkl:
        Add XSLTExtensions.{h,cpp} to projects.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@24088 268f45cc-cd09-0410-ab3c-d52691b4dbfc