Speedrunning utilities for race modes

[yellowberryHN]

Speedrun clock for parkour/race modes, among other features.

• [ ] Speedrun clock (starts when start ent is touched)
• [ ] Keep track of current checkpoint as static memory
• [ ] Add speedrunning options
• [ ] Add option to automatically respawn after death
• [ ] Minimize frame lag and input lag

Some references: https://www.reddit.com/r/speedrun/comments/7dt0rh/gamedev_looking_for_speedrunner_advice/ https://forum.speeddemosarchive.com/post/what_features_should_a_developer_put_in_their_game_for_speedrunners.html https://kb.speeddemosarchive.com/Making_your_game_speedrunner-friendly