Extend improvement destruction to all attack types, up destruction

[Ogaden]

Air attacks should actually be the most likely to destroy an improvement.  Currently only ground attacks, missiles and nukes destroy improvements.

 

Improvement destruction should be extended as follows:

First of all, double the current chance to destroy an improvement of conventional ground attacks, then:

 

Air attack: double improvement destruction chance compared to ground attack

navy attack: 50% more likely to destroy an improvement compared to a ground attack

ground attack: normal improvement destruction

missile: at least 1 and 50% chance of 2 improvements destroyed

nuke: at least 2 and up to 5 improvements destroyed

[Magnanimus]

I think Improvement destruction should only be limited to Nukes, Navy attack and Air-strikes that are not dog-fights.

 

Rest all should not touch improvements but the destruction to soldiers and tanks can be beefed up.

[Atzuya]

20% chance to destroy an improvement with airstrikes would get things super interesting