Version 0.5.3

Small optimisations release:

• ari edelkind (@edelkind) contributed a speed-up optimisation for handling of files
  without xattrs (which is, in general, the expected case)
• Jonas Borgström (@jborg) contributed a behaviour change to the handling of file
  names: under Python 3 and up, unicode paths are encoded/decoded using
  the 'surogatee' handler, instead of the 'strict' handler; while this
  can hide encoding errors, it mirrors what Python libraries do
  (e.g. see os.fsencode/fsdecode)
• Sean Patrick Santos (@quantheory) contributed improvements to the test suite so that
  it can be used even on files systems which have built-in attributes
  (e.g. when using SELinux, or NFSv4); to enable this, define the
  attributes in the TEST_IGNORE_XATTRS environment variable