Use the current position for projectile explosions. Fixes #3795.
Restore original sound parameters. Fixes #3919.
Remove Game.Zoom.
Fix the pip/tag/group decoration size when zooming.
Fix the rank chevron size when zooming.
fix/balance RA map Athena

1. Reduced strategic victory timer from 10 to 3 minutes to increase
pressure on players.
2. Increased the size of the starting islands in order to give a player
more strategic options.

Removed *Options: OpenRA.MapOptions* as seen in
https://github.com/OpenRA/OpenRA/pull/3939. Checked all starting
positions in-Game.
Merge pull request #3946 from wuschel/bleed

fix/balance RA map Athena (koth)
Merge pull request #3945 from pchote/zoom-fix

Prevent pixel doubling of group / pip / tag / chevron decorations.
Merge pull request #3944 from pchote/sound-fix

Fix bogus sound attenuation.
Merge pull request #3943 from pchote/wall-fix

Fix projectiles vs walls.