Enhanced CTorrent Code

tag dtorrent-3.3 (ctorrent-dnh3.3)

dnh3.3 release update

Include config.h in bitfield.cpp

Support systems that do not supply random(3).

Fix unlikely but potential division by zero in Prefetch.

m_err_count should be int to handle reduction

Reduce peer error count on piece completion

Correct messages that should be Debug instead of Warning

HealthCheck improvement to reduce redundant receipts from high latency peers.

Improve choke oscillation detection to reduce duplicate (redundant) receipts.