Changes since
- dropped depenency on iconv
- deprecate set_file_hash() in torrent creator, as it's superceded by v2 torrents
- deprecate mutable access to info_section in torrent_info
- removed deprecated lazy_entry/lazy_bdecode
- stats_alert deprecated
- remove bittyrant choking algorithm
- update userdata in add_torrent_params to be type-safe and add to torrent_handle
- add ip_filter to session_params
- added support for wolfSSL for SHA-1 hash and HTTPS (no Torrents over SSL)
- requires OpenSSL minimum version 1.0.0 with SNI support
- deprecated save_state() and load_state() on session in favour of new
write_session_params() and read_session_params() - added support for BitTorrent v2 (see docs/upgrade_to_2.0.html)
- create_torrent() pad_file_limit parameter removed
- create_torrent() merkle- and optimize-alignment flags removed
- merkle_tree removed from add_torrent_params
- announce_entry expose information per v1 and v2 info-hash announces
- deprecated sha1_hash info_hash members on torrent_removed_alert,
torrent_deleted_alert, torrent_delete_failed_alert and add_torrent_params - undeprecate error_file_metadata for torrent errors related to its metadata
- remove support for adding a torrent under a UUID (used for previous RSS support)
- remove deprecated feature to add torrents by file:// URL
- remove deprecated feature to download .torrent file from URL
- requires boost >= 1.66 to build
- update networking API to networking TS compatible boost.asio
- overhauled disk I/O subsystem to use memory mapped files (where available)
- libtorrent now requires C++14 to build
- added support for GnuTLS for HTTPS and torrents over SSL