* Changed some interception-related uniques
- "Can not be intercepted" -> "Cannot be intercepted"
This really irked me, and the new version is also how it is written
in the wiki.
- "Reduces damage taken from interception by 50%" ->
"Damage taken from interception reduced by [50]%"
* Added "Cannot be carried by [unitFilter] units" unique
* Added an icon for Stealth
* Added Stealth technology and the Stealth Bomber
* Possibly fixed incorrect rounding for interception damage bonus
* Various code style changes
* Made Stealth Bomber interceptable, but with 100% damage reduction
