sixel graphics support

[Գասպար Վարդանյան]

Please apply the sixel-grephics feature (as an compile-time conditional feature).
The sixel-grephics repository:  https://github.com/saitoha/libsixel
rxvt-unicode with the sixel-graphics added:  https://github.com/saitoha/rxvt-unicode-sixel
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.schmorp.de/pipermail/rxvt-unicode/attachments/20200206/8c1fe32f/attachment.htm>