Tag to be used with the master branch of atlas/athena. Update(s) since 2.0.64: - Forced GeoModelCore to be built with optimisations, even in Debug builds; - Updated the AtlasLCG modules to consistently set up <PACKAGE>_<executable>_EXECUTABLE variables for externals that provide executables; - Updated FindXercesC.cmake to wrap CMake's own FindXercesC.cmake module; - Updated GPerfTools to use Findgperftools.cmake instead of Findtcmalloc.cmake; - Updated atlas_build_run.sh to handle quoted commands correctly; - Fixed the build of Python 2.7 on systems that don't provide Python 2 in /usr; - Updated GDB to version 9.1; - Command-line usage improvements in flake8_atlas; - Removed the EXTRA_PATTERNS argument from atlas_add_test(...).