Don't attempt to use sizeof() on a pointer

The change added in 279058d8 never actually worked, because
calling sizeof() on a pointer to a buffer does not in fact get you
the size of the buffer.  (Rather, it worked fine provided you
didn't want more than 8 bytes back.)

Update pioctl_write() to take a parameter for the size of the
output buffer, and update calls to pioctl_write in _fs.pyx and
_acl.pyx
Release 0.2.1
Remove Debian packaging from master
Fix error handling in pioctl wrappers

We need to save the value of errno if we hope to do anything useful
with it, otherwise logging will scribble over it.
Release 0.2.2

Release 0.2.2 with pioctl wrappers that actually save errno