add streamed file size to console output

I think this is useful. It just changes the console output from 
info streaming Almost.Human.S01E01.HDTV.x264-LOL.mp4 - 76.8KB/s from 6/27 peers
to
info streaming Almost.Human.S01E01.HDTV.x264-LOL.mp4 (329.4MB) - 76.8KB/s from 6/27 peers
it adds the (329.4MB)