HUD Updates and Timing Bugs

HUD Screenshot

The HUD now renders armor, health and current ammo counts in addition to the per-ammo type display at the top. The latter uses conchars, which, as the name suggests, are used for rendering text to the in-game console. Now that I can load and display these I can start working on the console, which ought to make debugging a great deal easier.

Unfortunately, the client is still plagued by a bug with position lerping that causes the geometry to jitter back and forth. This is most likely caused by bad time delta calculations in Client::update_time() (Github), but I haven't been able to pinpoint the exact problem -- only that the lerp factor seems to go out of the expected range of [0, 1) once per server frame. I'll keep an eye on it.