Re: monotone 1.2 release?

I didn't have really the time (to form the) knowledge to update myself 
to Botan 3, and since Mistral launched Devstral2:123B (temporarily for 
free) a few days ago I decided to try it on this task. And it worked!

I will review the changes and remove anything unnecessary (or wrong) 
during the weekend, but in the meantime I committed the "raw" result:

Revision: ea8769d1048fddca749f4e9fdc8238027c8272f9
Branch:   net.venge.monotone.lapo.botan3

Changelog:

Update from Botan2 to Botan3.

These are the pure changes made by Devstral2:123B with a few iterations, 
some of which I will try to factor out.

Prompts used (I don't remember exactly):
1. this is a project depending on obsolete Botan 2 library, please 
update it to Botan 3
2. the code does not work, use "make" and solve the problems
3. now it build but it has runtime problems, use "./mtn st" and solve 
the problems

This experiment took ~10 minutes of my time over a span of a few hours 
and 23 Mtokens (around 46$ if it wasn't free at the moment).