merged encryption patch from RC_0_16

ChangeLog

@@ -20,6 +20,7 @@
 	* fix uTP edge case where udp socket buffer fills up
 	* fix nagle implementation in uTP
 
+	* try unencrypted connections first, and fall back to encryption if it fails (performance improvement)
 	* add missing functions to python binding (flush_cache(), remap_files() and orig_files())
 	* improve handling of filenames that are invalid on windows
 	* support 'implied_port' in DHT announce_peer

docs/manual.rst

@@ -608,7 +608,7 @@ manually control when the torrent leaves upload mode, don't make it auto managed
 
 ``flag_share_mode`` determines if the torrent should be added in *share mode* or not.
 Share mode indicates that we are not interested in downloading the torrent, but
-merlely want to improve our share ratio (i.e. increase it). A torrent started in
+merley want to improve our share ratio (i.e. increase it). A torrent started in
 share mode will do its best to never download more than it uploads to the swarm.
 If the swarm does not have enough demand for upload capacity, the torrent will
 not download anything. This mode is intended to be safe to add any number of torrents

src/policy.cpp

@@ -1859,7 +1859,11 @@ namespace libtorrent
 		, trust_points(0)
 		, source(src)
 #ifndef TORRENT_DISABLE_ENCRYPTION
-		, pe_support(true)
+		// assume no support in order to
+		// prefer opening non-encrypyed
+		// connections. If it fails, we'll
+		// retry with encryption
+		, pe_support(false)
 #endif
 #if TORRENT_USE_IPV6
 		, is_v6_addr(false)