Reviewed by Maciej.

        Adding tests for http://bugzilla.opendarwin.org/show_bug.cgi?id=8121
        REGRESSION: 404s are not displayed
        and http://bugzilla.opendarwin.org/show_bug.cgi?id=7739
        REGRESSION: Assertion failure loading acid2 test in -[WebCoreFrameBridge installInFrame:]

        In addition I tweaked the httpd conf file to allow us to exec perl CGI scripts.

        * http/conf/httpd.conf:
        * http/tests/misc/error404-expected.checksum: Added.
        * http/tests/misc/error404-expected.png: Added.
        * http/tests/misc/error404-expected.txt: Added.
        * http/tests/misc/error404.pl: Added.
        * http/tests/misc/iframe404-expected.checksum: Added.
        * http/tests/misc/iframe404-expected.png: Added.
        * http/tests/misc/iframe404-expected.txt: Added.
        * http/tests/misc/iframe404.html: Added.

WebCore:

        Reviewed by Maciej.

        Support for fixing http://bugzilla.opendarwin.org/show_bug.cgi?id=8121
        REGRESSION: 404s are not displayed

        * bridge/mac/WebCoreFrameBridge.mm:
        (-[WebCoreFrameBridge currentForm]): Nuke redundant nil check.
        (-[WebCoreFrameBridge frameElement]): Tweak to not rely on our document, which
        gives a correct result even at the start of our loading process.
        * bindings/objc/DOM.mm:
        (-[DOMDocument _ownerElement]): Nuke redundant nil check.

WebKit:

        Reviewed by Maciej.

        fix http://bugzilla.opendarwin.org/show_bug.cgi?id=8121
        REGRESSION: 404s are not displayed

        * WebView/WebMainResourceLoader.m:
        (-[WebMainResourceLoader continueAfterContentPolicy:response:]):
        Only cancel failed loads for object elements, not for frames or a whole page.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@13650 268f45cc-cd09-0410-ab3c-d52691b4dbfc