Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.109:
  - Made it possible to build ROOT with LLVM/Cling in Debug mode for dictionary debugging;
  - Removed the build of FastJet from all of the LCG based projects;
    * At the same time switched the build of FastJet in AnalysisBaseExternals to version 3.4.0, in sync with LCG_100_ATLAS_5;
  - Upgraded lwtnn to version 2.12;
  - Upgraded prmon to version 2.2.1;
  - Removed some unnecessary printouts from the build of dictionaries and converters.