in experimental single project build we see these identically named files installed from egammapidtools and photonanalysisutils
in practice this means that in a release one or another will be used according to the way the env is set up. 
it should be fixed by removing the duplication.

physicsanalysis_standardmodelphys_photonanalysisutils.loglog:atlas_check_installations.sh: error: photonlikelihoodpdf.root already installed from different source /build/newrelease/atlasoffline/rel_2/reconstruction/egamma/egammapidtools/share
