libtorrent 0.14.4

libtorrent is a C++ implementation of the BitTorrent protocol with the goals of being efficient and easy to use.
libtorrent is a C++ library that aims to be a good alternative to all the other bittorrent implementations around.
Although it comes with a working example client, libtorrent is a library and not a full featured client.
The main goals of libtorrent are:
- to be cpu efficient
- to be memory efficient
- to be very easy to use
libtorrent has been successfully compiled and tested on:
- Windows 2000 vc7.1, vc8
- Linux x86 GCC 3.3, GCC 3.4.2
- Mac OS X (darwin), (Apples) GCC 3.3, (Apples) GCC 4.0
- Sun OS 5.8 GCC 3.1
- Cygwin GCC 3.3.3
NOTE: libtorrent is licensed and released under the BSD-license.

Main features:
- trackerless torrents (using the Mainline kademlia DHT protocol) with some DHT extensions.
- support for IPv6
- NAT-PMP and UPnP support (automatic port mapping on routers that supports it)
- piece-wise, unordered, incremental file allocation
- uses separate threads for checking files and for main downloader, with a fool-proof thread-safe library interface. (i.e. Theres no way for the user to cause a deadlock). (see threads)
- adjusts the length of the request queue depending on download rate.
- multitracker extension support (as specified by John Hoffman)
- supports files > 2 gigabytes.
- serves multiple torrents on a single port and in a single thread
- fast resume support, a way to get rid of the costly piece check at the start of a resumed torrent. Saves the storage state, piece_picker state as well as all local peers in a separate fast-resume file.
- HTTP seeding, as specified by Michael Burford of GetRight.
- piece picking on block-level (as opposed to piece-level). This means it can download parts of the same piece from different peers. It will also prefer to download whole pieces from single peers if the download speed is high enough from that particular peer.
- supports the udp-tracker protocol by Olaf van der Spek.
- queues torrents for file check, instead of checking all of them in parallel.
- supports http proxies and basic proxy authentication
- gzipped tracker-responses
- can limit the upload and download bandwidth usage and the maximum number of unchoked peers
- implements fair trade. User settable trade-ratio, must at least be 1:1, but one can choose to trade 1 for 2 or any other ratio that isnt unfair to the other party.
- supports an extension protocol. See extensions.
- supports the no_peer_id=1 extension that will ease the load off trackers.
- possibility to limit the number of connections.
- delays have messages if theres no other outgoing traffic to the peer, and doesnt send have messages to peers that already has the piece. This saves bandwidth.
- does not have any requirements on the piece order in a torrent that it resumes. This means it can resume a torrent downloaded by any client.
- supports the compact=1 tracker parameter.
- selective downloading. The ability to select which parts of a torrent you want to download.
- ip filter to disallow ip addresses and ip ranges from connecting and being connected

Enhancements
- connect candidate calculation fix
- tightened up disk cache memory usage
- fixed magnet link parser to accept hex-encoded info-hashes
- fixed inverted logic when picking which peers to connect to
- (should mean a slight performance improvement)
- fixed a bug where a failed rename_file() would leave the storage
- in an error state which would pause the torrent
- fixed case when move_storage() would fail. Added a new alert
- to be posted when it does
- fixed crash bug when shutting down while checking a torrent
- fixed handling of web seed urls that didnt end with a
- slash for multi-file torrents
- lowered the default connection speed to 10 connection attempts
- per second
- optimized memory usage when checking files fails
- fixed bug when checking a torrent twice
- improved handling of out-of-memory conditions in disk I/O thread
- fixed bug when force-checking a torrent with partial pieces
- fixed memory leak in disk cache
- fixed torrent file path vulnerability
- fixed upnp
- fixed bug when dealing with clients that drop requests (i.e. BitComet)
- fixes assert as well