Option to disable build timestamps

[dawkagaming]

Hello,

would it be possible to add a CMake option to disable adding the build timestamp inside the credits?

This can make reproducible builds, and as such it is quite important to make it optional.

I am already patching it in the Debian packaging, but would love to see it in the upstream.

Thanks
Dawid SP9SKA

[dawkagaming]

Also it would be nice to have an option, when choosing to build with some feature that need a library from third_party add an opt-in option to use system libraries, like zlib (as it would be preferable to use the Debian archive library if possible).

Thanks again!