Change two `constexpr` declarations to `inline` to fix a link error on
MSVC.
Also remove the C++14 override that was used for testing on MSVC, the
project being defined as C++17 in CMake.
Signed-off-by: Rafael Kitover <rkitover@gmail.com>
Convert the C++17 code in the bundled SFML code to C++14 to hopefully
allow for targeting macOS 10.10 (Yosemite) instead of 10.15 (Catalina.)
Signed-off-by: Rafael Kitover <rkitover@gmail.com>
Remove the SFML external dependency, include the SFML 3.0.1 system and
network libraries in third_party and adjust the build code, tools and
documentation accordingly.
Signed-off-by: Rafael Kitover <rkitover@gmail.com>
Rafael Kitover