Tag to be used ONLY WITH NIGHTLY BUILDS of the master branch of atlas/athena. Updates since 2.0.11: - Revived the "doc" target for Doxygen documentation generation; - Updated all "standalone" externals to versions in sync with LCG_94; - Upgraded to the (currently) latest version of yampl; - Added the build's CMake version to the generated ReleaseData file; - Upgraded to HDF5-1.10.3; - Patched CLHEP to remove build warnings with GCC 8; - Added FindLibXslt.cmake, and made Findtdaq.cmake use it; - Added a fix for the build time inconsistency that we had in ReleaseData.