Gwenview 2 moved to kdegraphics

[Aurélien Gâteau]

Allen Winter wrote:

> If libexiv2 is an optional dependency then gwenview should build without
> it. If libexiv2 is a hard dependency then obviously gwenview can't be
> built without it.
> 
> If optional, then I don't think the kdegraphics/CMakeLists.txt file is
> doing the right thing.

For now it's a hard dependency. So I think it's ok. I could probably change
it, but I'm not sure it's really needed.

Aurélien