Enhanced CTorrent Code

Improve idle-time scheduling and processing.

Update docs

Update docs

tag dtorrent-3.3.2 (ctorrent-dnh3.3.2)

Update version to 3.3.2

Remove unneeded buffer allocation in bencode_buf

Correction in I/O file determination.

When reading a piece for hash check, avoid expiring parts of the same piece from the cache.

Use staged data gaps to influence download piece selection.

Extra staging file list entry could be created due to max size.
Skip merging if staged data is already present in the target file.