DlangUI project update

[Vadim Lopatin via Digitalmars-d-announce]

On Tuesday, 30 December 2014 at 10:37:14 UTC, ketmar via 
Digitalmars-d-announce wrote:
> p.s. there is small glitch with checked checkboxes though: 
> image is not
> transparent.

I've created pull request for dlib with added support of 
transparency in indexed color PNGs.
Issue with non-transparent buttons will be fixed after pull 
request integration.