Log Message:
Update to 1.40.0

Upstream changes:
1.40.0 - 2018-01-25
-------------------

* APEv2: Ensures tags are saved in a deterministic way :pr:`329`
  (:user:`cushy007`)
* Restore WinXP support for the CLI tools :bug:`332`
* easymp4: Fix EasyMP4.add_tags() when no tags exist :bug:`334`
* id3: Fix PyCharm not being able to resolve id3 frame class references
  :bug:`336`
* Support pathlib.Path objects for paths (PEP 519) :bug:`337` :pr:`338`
  (:user:`Andrew Rabert <nvllsvm>`)
* Use semver for versioning