Follow doxygen.cfg from clang; fixes long paths in file mentions.
Follow doxygen.cfg from clang; fixes long paths in file mentions.

karies/cling,root-mirror/cling,karies/cling,karies/cling,karies/cling,root-mirror/cling,root-mirror/cling,root-mirror/cling,root-mirror/cling,karies/cling,karies/cling,root-mirror/cling