Reviewed by Maciej.

        - fix http://bugs.webkit.org/show_bug.cgi?id=15814
          <rdar://problem/5536644> fast/js/kde/encode_decode_uri.html fails

        These changes cause us to match the JavaScript specification and pass the
        fast/js/kde/encode_decode_uri.html test.

        * kjs/function.cpp: (KJS::encode): Call the UTF-8 string conversion in its
        new strict mode, throwing an exception if there are malformed UTF-16 surrogate
        pairs in the text.

        * kjs/ustring.h: Added a strict version of the UTF-8 string conversion.
        * kjs/ustring.cpp:
        (KJS::decodeUTF8Sequence): Removed code to disallow U+FFFE and U+FFFF; while
        those might be illegal in some sense, they aren't supposed to get any special
        handling in the place where this function is currently used.
        (KJS::UString::UTF8String): Added the strictness.

LayoutTests:

        Reviewed by Maciej.

        - updates for http://bugs.webkit.org/show_bug.cgi?id=15814
          <rdar://problem/5536644> fast/js/kde/encode_decode_uri.html fails

        * fast/js/kde/resources/encode_decode_uri.js: Rewrote the test to cover edges better,
        and use the should functions in a way that makes failures easier to understand.
        * fast/js/kde/encode_decode_uri-expected.txt: Updated.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@27406 268f45cc-cd09-0410-ab3c-d52691b4dbfc