fread argument `quiet=TRUE`

[rmscriven]

Hello. In fread, would you consider adding quiet = TRUE to the download.file argument list when showProgress = FALSE ? Question posted at the link below.

http://stackoverflow.com/questions/24924198/data-tablefread-delivers-download-message-when-no-download-should-occur

Cheers.

[mattdowle]

Thanks @kbroman for the pull request - accepted. Very nice.