jrandom authored 20 years ago and zzz committed 20 years ago

* added more inbound tests
* made the tunnel preprocessing header more clear and included better fragmentation support
(still left: tests for outbound tunnel processing, structures and jobs to integrate with the router,
remove that full SHA256 from each and every I2NPMessage or put a smaller one at the
transport layer, and all the rest of the tunnel pooling/building stuff)