Usability Improvements (Patreon)

Been working on several usability improvements, including a better screenshot naming scheme. This naming format will make it easier to know which engine version was used, which game/mod was being played, and when. It completely eliminates numbering limitations, and allows screenshots of multiple mods to be put in the same folder (e.g. in a webserver) without mixing their order.

I'm also redesigning the network protocol flags to handle Retroquad's features. Right now, most of Retroquad-specific visual effects are configured globally through cvars, but soon they will be able to be configured individually for each entity.