[CMAKE] Get rid of the set_cpp macro

Instead of messing with global variables and the like, we introduce two target properties:
 - WITH_CXX_EXCEPTIONS: if you want to use C++ exceptions
 - WITH_CXX_RTTI: if you need RTTI in your module
You can use the newly introduced set_target_cpp_properties function, with WITH_EXCEPTIONS and WITH_RTTI arguments
We also introduce two libraries :
 - cpprt: for C++ runtime routines
 - cppstl: for the C++ standard template library

NB: On GCC, this requires to create imported libraries with the related built-in libraries:libsupc++, limingwex, libstdc++

Finally, we manage the relevant flags with the ad-hoc generator expressions

So, if you don't need exceptions, nor RTTI, nor use any runtime at all: you simply have nothing else to do than add your C++ file to your module

sdk/lib/drivers/sound/stdunk/CMakeLists.txt

@@ -1,4 +1,3 @@
 
-set_cpp()
 add_library(stdunk cunknown.cpp)
 add_dependencies(stdunk xdk)