xAOD::EventAuxInfo Schema Evolution, master branch (2020.01.30.)

After an e-mail thread with @tsulaia, @goetz and @ssnyder, we/I decided that the averageInteractionsPerCrossing and actualInteractionsPerCrossing variables of xAOD::EventInfo should become dynamic auxiliary variables. This will allow us to set them as decorations during RAW->ESD reconstruction, using a regular algorithm. (And not in the ByteStream converter.) So the only difference between xAOD::EventAuxInfo_v1 and xAOD::EventAuxInfo_v2 is that I removed those two float variables from the latter.

I tried to add and update the relevant tests. I also checked with some additional printouts in some test jobs that the pileup values seem to be read correctly into the _v2 auxiliary object correctly from old/current xAOD files. So I'm very confident that this update should "work". 😉

At the same time this is the first time that I'm using Scott's "T/P converter testing infrastructure", so he may have a comment about the code that I wrote.

BTW, Scott, you'll see that in the updated CMakeLists.txt file I search for your CMake code with the path ${CMAKE_SOURCE_DIR}/../../Database/AthenaPOOL/AthenaPoolUtilities. This is the correct path ever since we switched to Git. So I'm quite worried that many current converter packages, which use ${CMAKE_SOURCE_DIR}/Database/AthenaPOOL/AthenaPoolUtilities, are only working by chance at the moment... 😦