Tinc 1.1pre Ed25519 public key integration into generated hosts file.
debian/changelog
Removed union from struct string

Let the compiler figure out the best layout.
string_concatb(): do not explode if growby == 0
Replace ugly uintptr_t with size_t for sizes.
string_init(): init growby structure member only once
Keep debug info in binary debian package for easier debugging.
correctly init config->ed25519publickey
Standards-Version: 3.9.6