Handle shell meta-characters and check for errors in bzr_find_files_for_bzr

[Gavin Panella]

See the attached bundle (pushing my branch is breaking consistently, bug 302868 filed with bzr).

There's an XXX in bzr_find_files_for_bzr about checking for errors, so I've tried to address that. I've just made stderr go to the parent stderr, which is probably the simplest thing to do for now, and least surprising.

I've also changed the call to Popen to deal with shell meta-characters.

[Richard Gomes (frgomes)]

Please try this:

$ python setup.py sdist --formats=gztar,zip

see: http://docs.python.org/2/distutils/sourcedist.html