AthDerivationExternals Creation, 1.0 branch (2017.04.15.)
Since the AthDerivation project doesn't need a few of the externals built by AthenaExternals, it seemed best to introduce a specific externals project for it. To cut down on the build time of that project a bit more.
This new project was simply based on AthenaExternals, with a few packages removed from it.
I've been testing the project in https://gitlab.cern.ch/atlas/athena/merge_requests/695. And it seems to work well in that build.