[gthumb-list] support for HEIC containers

[grubernd <lists mehrzweckraum com>]

hi..

someone using an alternative operating system (something to do with 
fruits) just sent me a file with the extension HEIC.

thunar shows the thumb.

gthumb 3.5.2 does not show the thumb when entering the folder.

upon "open in gThumb" from the file manager i can see an alternating 
flickering between the thumb and the word "JPG".

does 3.5.3 support HEIC? i have not seen it been mentioned in the changelog.

if not, how can i make HEIC files work as the JPGs they are?


cheers,
grubernd