Allow more drag'n'drop DataObject formats

[CanyonJim]

Drag and drop from Windows Explorer and Directory Opus to the slide list panel works fine, but appears to rely on the "Shell IDList Array" DataObject format.  This format is very difficult to create in .Net programs (e.g. C# or VB.Net).  On the other hand it is very easy to add "FileDrop" and/or "FileNameW" formats to the DataObject in .Net.  Having implemented drag and drop using the "Shell IDList Array" format I would expect it to be fairly straight forward to handle the "FileDrop" and/or "FileNameW" formats as an alternative.

I am interested because I have a custom program written in C# that catalogs restores, manages, and annotates thousands of archival images.  I have no problem dragging and dropping files into Windows Explorer or Photoshop, but cannot get drag and drop to work properly with PicturesToExe.  I expect other people might have similar issues with other cataloging software.