Tag to be used with the master branch of atlas/athena. Updates since the last tag: - Fixed the dependency setup for generating .pyc files, which could produce a broken build setup in some cases previously; - Tweaked the logic of lcg_generate_env(...) not to print false warnings in some cases; - Updates to the GCC checker code from Scott; - Added a standalone version of Davix and updated the version of XRootD, updating the build of ROOT to use these new externals. Updated AthAnalysisExternals to build Davix and XRootD. - Updated GDB to version 8.1; - Removed DMTCP from the repository; - Updated all LCG based projects to LCG_93a.