patch that fixes the problem of building RooStats on Windows using CMake.
Somehow it was generating a too long command to generate the .def file.
At the same time I also have added sehmap.h in the distributions that
fixes the problem reported by people not having it in their installation.


git-svn-id: http://root.cern.ch/svn/root/trunk@48599 27541ba8-7e3a-0410-8455-c3a389f83636