added screed and read_parser streaming testing

Marked as known failing since they currently fail.
Will investigate.

Relevant to #393, #654
Ugh, the grammar here is awkward. More definite articles, please.

"Check the status of the file. If it is not empty or does not exist _and_ the file isn't a block device or a FIFO/named-pipe then a warning is printed and sys.exit(1) is called."