anchor: File:write
  Write data to a file.
  success, err = File:write( data, size )
  data string The string data to write.
  size (all) number How many bytes to write.
  success boolean Whether the operation was successful.
  err string The error string if an error occurred.
  success, errorstr = File:write( data, size )
  data Data The Data object to write.
  size (all) number How many bytes to write.
  success boolean Whether the operation was successful.
  errorstr string The error string if an error occurred.