- fixed 3 problems with parse functions that I just wrote, fixing 3 more Mozilla JavaScript tests

        * kjs/function.cpp:
        (KJS::parseDigit): Fix typo, 'Z' instead of 'z', that prevented lowercase hex digits from working.
        (KJS::parseInt): Add octal support. Specification says it's optional, but I guess not.
        (KJS::parseFloat): Fix check for "0x" in parseFloat to return 0 rather than NaN. Also add code
        to skip leading "+" or "-".


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@7245 268f45cc-cd09-0410-ab3c-d52691b4dbfc