Image List tests for comctl32 v6

[Joel Holdsworth]

> Do you mean that the tests pass on Windows but not Wine when using 
> load_v6_module, or that they don't pass on either platform? I used 
> load_v6_module for some v6 imagelist tests (which may not yet be merged 
> into Wine actually; I should probably check that and resubmit) and they 
> worked fine. You may want to look at http://tinyurl.com/ybo28lt for 
> instance.
>
> If the tests are working on Windows but not on Wine, the obvious reason 
> for your tests failing would be that the required alpha channel support 
> is not implemented.
> 
> Cheers,
> 

It sounds like I need to investigate further, but no - I'm only talking
about Windows. With crosstest, load_v6_module seems not to switch to v6
with regard to image lists.