Encapsulate net teardown logic.

Add context on all log items.

Put mocks to directory structure mimicking project structure.

Use abstraction instead of using SDL dependencies.

Ensure game/server configs sit in game directory for easy editing and referencing.

The logging for the network teardown has been put in the appropriate function.

Come up with our own logging system.

Tidy up CMake.

Also provide abstraction to fopen_s only available to Windows.

Include _s wrappers for most standard function calls.

Add compatibility for macOS and *NIX files

TODO: inspect building of dependencies

Ensure every config-backed subsystem can serialize/deserialize config in
a single consistent manner.

Add templates for config item types.

Also updated server's config to use the global config module.

Remove symlinks and make codebase use common modules instead.