Add a .gitignore file.
Fix several wrong arguments passed to liblo functions.
Only filter out -Werror, not -Werror=something

Prevents build failures, because the CFLAGS would contain =something in the arguments
Add lo::Address::send_from() overload for lo::ServerThread

To avoid implicit casting issues with lo_server/lo_server_thread.
Add Windows-related preprocessor flags to CXXFLAGS.
Some Windows-related ifdefs for cpp_test.cpp.
Add some missing exported functions for Windows DLL.
Fix config.h for no-threads premake option on Windows.
Fix time.h include on Windows.
Preprocessor error EADDRINUSE may be defined now in Windows.
Fix unknown pointer size in MSVC.