* Don't overwrite the CMAKE_MODULE_PATH
* Allow linking libsodium statically with MSVC
* Allow finding libsodium the normal way on MSVC
* Allow using pthreads4w for pthreads on MSVC
* Fall back to find_package if pkg_find_module fails
* Don't pass incompatible compile flags to MSVC
* Also try to find Opus and libvpx using their canonical names
* Support building using conan
* Allow pkg_use_module to take a list of libraries to look for
* Build for Windows on Appveyor using conan
