The downside is that the result_generator is difficult to ctrlc on
windows due to signals not occuring during the Queue.get. Pressing
ctrlc will kill the program after one file finishes downloading,
otherwise you have to press ctrlbreak. The end result is that the
program actually feels a little worse to use than before, but it's
more, like, pure. Don't know. Might revert or change again.
With pathclass.glob_many, we can clean up and feel more confident
about many programs that use pipeable to take glob patterns.
Added return 0 to all programs that didn't have it, so we have
consistent and explicit command line return values.
Other linting and whitespace.
