For "CarlaLIB" and "PythonAPI" don't check if the a build already exists, as the build check is done by the compiler and intallation check is done by cmake.
Stop build if any error was found
Enable multiprocess compilation
Add BuildPythonAPI.bat to makefile
Add BOOST_ALL_NO_LIB as workaround for https://github.com/boostorg/python/issues/193