fix ifdef around assert
fix assert in do_clear_piece
disable especially expensive asserts in release mode when release-asserts are on
fix race condition in outstanding_flush state
limit receive buffer size to 2 MB per peer
minor clean up of client_test's download list view
fix path sanitization bug
add stats counters for incoming and outgoing bittorrent messages, as well as adding it to session stats
fix parsing script for session_stats
update file list printing in client_test