[Development] Access to WebKit Internal API

[Alan Ng]

Hi, I am trying to access WebCore internal classes like the
RenderObject but they are not exported symbols in the final
Qt5Webkit.dll . Is there a simple/easy way to export all the symbols
in the build process? I hope I don't need to mark every classes with
export macro. I built Qt from git using MSVC 2012.

Thanks,
Alan