- Update to 0.16.12:
* fix building with C++11
* fix IPv6 support in UDP socket (uTP)
* increase max allowed outstanding piece requests from peers
* uTP performance improvement. only fast retransmit one packet at a time
* improve error message for 'file too short'
* fix piece-picker stat bug when only selecting some files for download
* fix bug in async_add_torrent when settings file_priorities
* fix boost-1.42 support for python bindings