#169 drag and drop files focus

[Brian Robb]

If you open the editor, then drag and drop a
script/image (maybe the other types too) it doesn't set
focus to the script/image

Perhaps it should give focus to the last file
drag/dropped? (If there's a list of files)

It's only really annoying for the script editor, it means
you can't drag, drop type, you have to drag, drop, click
then type...