This is a weird engine behaviour where draw3D doesn't work if the
current camera unit is not alive (or going to respawn), so we switch to
a temporary agent unit while in free camera to work around this edge
case.
* Fix incorrect function input for spectator hiding
* Remove locations tab from spectator
- Doesn't add much value, adds complexity and the implementation is half
baked. Would rather add back in at a later date (if at all) with a
better implementation.
- I have an idea to replace the locations tab with a meta tab so users
can toggle things like projectile drawing via the UI and are not forced
to use a hotkey. Might also be a good place to display the extended controls.
- Overhauls the spectator module entirely to share a similar UX to BI's "End Game Spectator" while maintaining some of the extended flexibility of ACE Spectator.
- Simplifies spectator setup by reducing the number of settings. More advanced setup is still possible via the API functions provided.
