socket: check sockId before train

never occured, but let's be defensive for ultimate stability :-)
peer: stealing compares peer's bestRate
store: fillInterestingPieces() invokes onPieceMissing() to get idle peers back up running
rm debug
peer: request timeouts simply depend on store's READAHEAD_TIME
ui css: don't scroll peers list
torrent: connectPeerLoop() with min/max peers limits