Reviewed by Maciej.

    Reviewed by Maciej.

        - fixed http://bugzilla.opendarwin.org/show_bug.cgi?id=3397
          Build DumpRenderTree fails with unresolved NSAutoreleasePool, etc

        * DumpRenderTree/DumpRenderTree.xcode/project.pbxproj: Change type from "folder" to "wrapper.framework"
        for Foundation.framework. How was it ever wrong?

        - finally, I tested making the default build directory work; it works now

        * Scripts/webkitdirs.pm: Changed structure of the code a little bit, added symrootXcodeOptions function
        that sets SYMROOT on the command line in case there's no product directory set in Xcode preferences.
        * Scripts/build-webkit: Pass symrootXcodeOptions when invoking Xcode.
        * Scripts/build-dumprendertree: Ditto.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@9348 268f45cc-cd09-0410-ab3c-d52691b4dbfc