I broke out the headers checking into a separate project. Its primary purpose is to detect unnecessary includes.
The headers checking was among the first Cppcheck checks. It has been disabled for years because it doesn't work with the Cppcheck data.
Adapting the Cppcheck data for the headers checking would be complicated and it would involve disabling the Preprocessor - and that is not acceptable. Therefore it was broken out into a separate project.
I recommend you download and try checkheaders. The webpage is: http://code.google.com/p/checkheaders
This project is supposed to be compatible with Cppcheck. Existing plugins should be able to execute checkheaders and parse the generated report with minor modifications.