I see someone else has got there before me and my answer would not be dissimilar.
Stuff to be able to talk to web services (because let's face it, any modern software will be doing that) is the obvious low hanging fruit, i.e. HTTP, JSON, Crypto etc.
Beyond that (if its not there already) basic tools to enable out-of-the-box CLI writing (e.g. flags etc.)
The problem with adding this is that in 10-20 years it's not so useful anymore. Then you'd have:
* an outdated HTTP library (look at how "everyone" is using a 3rd party HTTP library in python)
* a JSON library no one uses (everyone used XML, now it's out of fashion. And JSON has obvious problems!)
* Old cryptographic standards that you'd rather not use
Perfect reason for not writing any software. None would work for 20 years without maintenance (there are some exceptions of course).