Libtorrent

* save both file and piece priorities in resume file
* added missing stats_metric python binding
* uTP connections are no longer exempt from rate limits by default
* fix exporting files from partfile while seeding
* fix potential deadlock on Windows, caused by performing restricted
tasks from within DllMain
* fix issue when subsequent file priority updates cause torrent to stop

* coalesce reads and writes by default on windows
* fixed disk I/O performance of checking hashes and creating torrents
* fix race condition in part_file
* fix part_file open mode compatibility test
* fixed race condition in random number generator
* fix race condition in stat_cache (disk storage)
* improve error handling of failing to change file priority
The API for custom storage implementations was altered
* set the hidden attribute when creating the part file
* fix tracker announces reporting more data downloaded than the size of the torrent
* fix recent regression with force_proxy setting

* don't perform DNS lookups for the DHT bootstrap unless DHT is enabled
* fix issue where setting file/piece priority would stop checking
* expose post_dht_stats() to python binding
* fix backwards compatibility to downloads without partfiles
* improve part-file related error messages
* fix reporting &redundant= in tracker announces
* fix tie-break in duplicate peer connection disconnect logic
* fix issue with SSL tracker connections left in CLOSE_WAIT state
* defer truncating existing files until the first time we write to them
* fix issue when receiving a torrent with 0-sized padfiles as magnet link
* fix issue resuming 1.0.x downloads with a file priority 0
* fix torrent_status::next_announce
* fix pad-file scalability issue
* made coalesce_reads/coalesce_writes settings take effect on linux and windows
* use unique peer_ids per connection
* fix iOS build on recent SDK
* fix tracker connection bind issue for IPv6 trackers
* fix error handling of some merkle torrents
* fix error handling of unsupported hard-links

* deprecate save_encryption_settings (they are part of the normal settings)
* add getters for peer_class_filter and peer_class_type_filter
* make torrent_handler::set_priority() to use peer_classes
* fix support for boost-1.66 (requires C++11)
* fix i2p support
* fix loading resume data when in seed mode
* fix part-file creation race condition
* fix issue with initializing settings on session construction
* fix issue with receiving interested before metadata
* fix IPv6 tracker announce issue
* restore path sanitization behavior of ":"
* fix listen socket issue when disabling "force_proxy" mode
* fix full allocation failure on APFS

* fix infinite loop when parsing certain invalid magnet links
* fix parsing of torrents with certain invalid filenames
* fix leak of torrent_peer objecs (entries in peer_list)
* fix leak of peer_class objects (when setting per-torrent rate limits)
* expose peer_class API to python binding
* fix integer overflow in whole_pieces_threshold logic
* fix uTP path MTU discovery issue on windows (DF bit was not set correctly)
* fix python binding for torrent_handle, to be hashable
* fix IPv6 tracker support by performing the second announce in more cases
* fix utf-8 encoding check in torrent parser
* fix infinite loop when parsing maliciously crafted torrents
* fix invalid read in parse_int in bdecoder (CVE-2017-9847)
* fix issue with very long tracker- and web seed URLs
* don't attempt to create empty files on startup, if they already exist
* fix force-recheck issue (new files would not be picked up)
* fix inconsistency in file_priorities and override_resume_data behavior
* fix paused torrents not generating a state update when their ul/dl rate
transitions to zero

* corrected missing const qualifiers on bdecode_node
* fix changing queue position of paused torrents (1.1.3 regression)
* fix re-check issue after move_storage
* handle invalid arguments to set_piece_deadline()
* move_storage did not work for torrents without metadata
* improve shutdown time by only announcing to trackers whose IP we know
* fix python3 portability issue in python binding
* delay 5 seconds before reconnecting socks5 proxy for UDP ASSOCIATE
* fix NAT-PMP crash when removing a mapping at the wrong time
* improve path sanitization (filter unicode text direction characters)
* deprecate partial_piece_info::piece_state
* bind upnp requests to correct local address
* save resume data when removing web seeds
* fix proxying of https connections
* fix race condition in disk I/O storage class
* fix http connection timeout on multi-homed hosts
* removed depdendency on boost::uintptr_t for better compatibility
* fix memory leak in the disk cache
* fix double free in disk cache
* forward declaring libtorrent types is discouraged. a new fwd.hpp header is provided