Don't use passes anymore for indirect lighting, people were using this
probably thinking it would do bounces, but that's not the intention of
this feature, it is to reduce problems with light bleeding. I want to
remove this option for AO as well, but will leave it in for now until
there is a better alternative.
Added bounces option for indirect, could be implemented much better,
but perhaps useful for testing now. Existing files need to set this to
1 to get the same results again.