Created attachment 3104 
A little patch that makes opening files faster.

I noticed that opening a large number of files with Ristretto is a bit slow. It takes about 16 seconds to open a directory with 510 JPEG files (total size about 870MB) on my computer. But if you select those files (through 'open file' not 'open folder') it will freeze for about 4 minutes.

I figured out that you can speed up to 8 seconds by reading EXIF data when you really nead it (when you try to access image's orientation) rather than when you create image object (rstto_image_new). 

Also, this 4 minute freeze comes from GtkRecentManager. It's very, very slow when you add many files at one. And if you open 500 files at once, then you're probably not going to view them all, right? Than maybe it makes no sense to add them all to "recent files"?

So, you can call gdk_recent_manager_add_*** when image is displayed, not when it's opened. That's how other viewers work, and it seems reasonable to me.

I implemented both changes -- see attached patch. It should work with version from August 22.