Currently bup only indexes physical parent paths; adjust tests.

Fix tests that fail on systems where components of the parent path are
symlinks (like /tmp on OS X).  i.e. if you run:

  bup index /x/y/z

bup might actually store

  /a/z...

if y is a symlink to a.  See index-cmd.py and index.reduce_paths().

Signed-off-by: Zoran Zaric <zz@zoranzaric.de>
[rlb@defaultvalue.org: handle test.sh fix differently; add realpath();
 adjust commit message.]
Signed-off-by: Rob Browning <rlb@defaultvalue.org>
_create_via_common_rec: treat rmdir() EEXIST like ENOTEMPTY.

See rmdir(2):

       ENOTEMPTY
              pathname contains entries other than .  and ..  ; or,
              pathname has ..  as its final component.  POSIX.1-2001
              also allows EEXIST for this condition.

Signed-off-by: Rob Browning <rlb@defaultvalue.org>
_apply_linux_attr_rec: treat ENOSYS like EOPNOTSUPP (seen via sshfs).

After reports that set_linux_file_attr() produces ENOSYS on sshfs,
raise raise ApplyError for ENOSYS too.

Signed-off-by: Rob Browning <rlb@defaultvalue.org>