Reviewed by Maciej.

    Reviewed by Maciej.

        - fixed uses of NULL in non-pointer contexts

        * khtml/khtml_part.cpp: (findWordBoundary): Changed NULL to 0 and did a little code
        cleanup of the surrounding code.
        * khtml/rendering/break_lines.cpp: (khtml::isBreakable): Changed NULL to 0 and did
        a tiny bit of cleanup.

        * WebCorePrefix.h: Add a definition of NULL here that takes advantage of the GNU
        __null feature even if the system C library doesn't.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@5269 268f45cc-cd09-0410-ab3c-d52691b4dbfc