Limit drag-and-drop of image files or opening them from Open File dialog to be only one file. If multiple files are selected or dropped, then only non-image files get opened. If all of them are image files, then the last image file gets opened.
Make some changes based on review comments.
Unit tests for dropping image files in Brackets.
Add some comments and refactor file filtering code into a function in DragAnd Drop util file.
Merge pull request #5634 from adobe/rlim/drag-and-drop-images

Limit drag-and-drop of image files or opening them from Open File dialog...