Reference Lambert W Implementation

A robust reference implementation of the Lambert W function.

Building on Windows

This library depends on flint, MPFR and sleef. Since MPFR uses a make buildsystem, I recommend using vcpkg to manage this on Windows.

First, use vcpkg to install mpfr and pkgconf
Download, build, and install flint and sleef (from source or using vcpkg)
Make sure to specify the following CMake variables before configuring
- CMAKE_TOOLCHAIN_FILE = {VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake
- PKG_CONFIG_EXECUTABLE = {VCPKG_ROOT}/installed/x64-windows/tools/pkgconf/pkgconf.exe