Updating from easylogging++ 9.89 to 9.96.7 turns it from a header only
library to one requiring a source file. It has been added to sources
near the other third party includes in the QMAKE to signify that it
isn't a first party file.
Updating easylogging++ also means that clang-msvc can compile without
any warnings, hence turning on warnings as errors for that compiler as
well, to avoid any regressions.
This is the newest version that doesn't lead to compile errors. It has
also reduced the amount of "-Wexpansion-to-defined" errors on clang-msvc
by about 80 (from ~400 to 320).
Vasily
matzman