sorting name of images based on name

[mohammad69h94]

• OS: windows
• PyQt version: Hi , when open labelimg and load images. images are not sorted and loaded in the program below: test\cucumber1.jpg test\cucumber10.jpg test\cucumber100.jpg test\cucumber101.jpg test\cucumber102.jpg test\cucumber103.jpg test\cucumber104.jpg test\cucumber105.jpg test\cucumber106.jpg test\cucumber107.jpg test\cucumber108.jpg test\cucumber109.jpg test\cucumber11.jpg test\cucumber110.jpg test\cucumber111.jpg test\cucumber112.jpg test\cucumber113.jpg test\cucumber114.jpg test\cucumber115.jpg test\cucumber116.jpg test\cucumber117.jpg test\cucumber118.jpg test\cucumber12.jpg test\cucumber120.jpg

[lgov]

PR #436 sorts file names in the list (automatically) in natural order instead of alphabetical order.

[turowicz]

@mohammad69h94 @lgov would be good to be able to sort by date modified also