shell32: Implement Set/GetCurrentViewMode in the default shellview.

[Nikolay Sivov]

  On 7/17/2010 21:20, David Hedberg wrote:
> Thanks for the pointers, I'll see if I can expand the tests somewhat
> and send a new version, probably simply using the local SetStyle
> helper (unless the tests shows something really weird).
I realized that probably not all modes could be supported with v5 
controls. So yes, a messaging test would be useful.