Patch for XFT support

[ChanderG]

Thanks for this Slock fork.

I came across this from this Reddit thread: https://libredd.it/momw76 and actually wanted Xft support myself. Have adjusted the patch you mention there to work with your version in this commit here: https://github.com/ChanderG/slock-1/commit/be2b309397d86c693597327354cb8ed8a3a63f38

I can open a PR if you need it. Otherwise, feel free to close this issue and this can just be a pointer to anyone else who wants this functionality.