#143 Display stops when a new picture is added to a large list

[Anonymous]

With a list of about 500 pics, if a new one is added the display stops loading pics while the list on the left refreshes.

The refresh needs to be moved to it's own thread and done in a way so it updates without changing the list too much. Like losing your place because the list scrolls up.

This is helpful when you have a automated program storing pics in a folder at regular intervals.