"Professional CMake" book suggest the following:
"Targets should build successfully with or without compiler support for precompiled headers. It
should be considered an optimization, not a requirement. In particular, do not explicitly include a
precompile header (e.g. stdafx.h) in the source code, let CMake force-include an automatically
generated precompile header on the compiler command line instead. This is more portable across
the major compilers and is likely to be easier to maintain. It will also avoid warnings being
generated from certain code checking tools like iwyu (include what you use)."
Therefore, removed the "#include <PreCompiled.h>" from sources, also
there is no need for the "#ifdef _PreComp_" anymore
translate()'s third argument is an optional string used as a comment:
"None" is a valid value for this argument (and is indeed the stated
default in the documentation), but as originally written it was not
accepted, only actual strings were allowed. This commit modifies the
format string from "s" to "z", allowing an explicit None argument.
