Several functions make program unresponsive

[ftphikari]

When I press Ctrl+L on my user folder I wait several seconds until it finishes, while the program is unresponsive. This is not a desired behavior, program should give status update to the user in a form of a progress-bar/etc, and it definitely should not hang, but do its business on a separate thread or something. Same thing with quick view, it should not hang the program while it loads the preview, it should show placeholder text like "image is loading"/progress-bar/etc, and the program should be responsive in the meanwhile.