Update to v40

This merge request will bring gnome-clocks up to v40, still including the patches from the prior version (in a rebased form).

I'm very green when it comes to open source contributions, gitlab, and honestly this type of coding, but want to learn(I'm learning this stuff as I go). So please, if there are things I could be doing better I want to hear it!

(I've had to step away from this for now due to personal reasons. Hopefully I hope to be able to start up on it again in about a month)