Use IZ_ prefix for constants.

Demonstrate on-the-fly flip for sprites.

TODO comments for implementation.

Make distinctions between internal and external (downloaded from
third-party servers).

Make use of sprite loading to streamline the sprite management process.

The sprites are now loaded using a utility function in IZ_video.

The magazines for each weapon except the rifles have been drawn.

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.

Rename files in order to prepare for extraction for publishing
subsystems independently.

Make the member name generic to accommodate other potential
implementations beyond Websockets.

Provide the facility for the player to retry a failed connection a
certain number of times.

Put input and video subsystems into their own directories.