SQLite version - AIR 1.0 vs 1.5 vs 2.0

I've come to understand that AIR uses its own built-in version of SQLite but

it's been hard to grasp what version is being used in each AIR version?

Has there been any upgrades to the SQLite version from 1.0 to 1.5 to 2.0beta?

I did notice that Nested Transactions are supported in the latest version but haven't

found any other changes - and it appears that the SQLite documentation still indicates

no support for Foreign Keys.

Thanks for any documentation pointers or version correlation you can provide.

Don