* refactor: add TR_PRIsv, TR_PRIsv_ARG macros
Like PRId64 and similar macros, these new macros are printf() helpers.
They are for passing std::string_views to printf()-like functions.
* refactor: move handshake_done args into a convenience struct
* refactor: move peer_id from peerIo to tr_handshake
tr_handshake is a short-term object and tr_peerIo is long-term, so this
effectively narrows the scope of this field.
* chore: remove unused field tr_peerIo.isEncrypted
* refactor: add tr_peer_id_t type to hold peer ids.
this is a 'using' alias to a std::array<> so that code passing peer-ids
around doesn't have to memcmp / memcpy PEER_ID_LEN anymore. Also removes
the now-unused PEER_ID_LEN macro.
Port libtransmission to C++. This PR doesn't refactor everything to c++.
Its code changes are only what was necessary to compile and link as c++.
See libtransmission/README.md for details on how to submit modernization
patches!
Co-authored-by: Mike Gelfand <mikedld@mikedld.com>
