advpack: Implement ExtractFiles

[Mike McCormack]

James Hawkins wrote:

> What is the policy about attaching changes to tests that pass because
> of a patch sent in?  Should I also diff the tests?

There's a higher level policy of "all changes should be atomic", which 
requires Wine to be in a working state before and after each change, so 
yes, you should update tests that pass with the patch that makes them pass.

If you're adding new tests, it makes sense to send them in a seperate 
patch after the patch that implements functionality to make the new 
tests pass.

Mike