Log Message:
py27-html-docs: Update lang/py27-html-docs to 2.7.15

Changes:
2.7.15
======
Documentation
-------------
- bpo-27212: Modify documentation for the :func:`islice` recipe to consume
  initial values up to the start index.
- bpo-32800: Update link to w3c doc for xml default namespaces.
- bpo-17799: Explain real behaviour of sys.settrace and sys.setprofile and
  their C-API counterparts regarding which type of events are received in
  each function. Patch by Pablo Galindo Salgado.
- bpo-8243: Add a note about curses.addch and curses.addstr exception
  behavior when writing outside a window, or pad.
- bpo-21649: Add RFC 7525 and Mozilla server side TLS links to SSL
  documentation.
- bpo-30176: Add missing attribute related constants in curses
  documentation.
- bpo-28929: Link the documentation to its source file on GitHub.
- bpo-26355: Add canonical header link on each page to corresponding major
  version of the documentation. Patch by Matthias Bussonnier.
- bpo-12067: Rewrite Comparisons section in the Expressions chapter of the
  language reference. Some of the details of comparing mixed types were
  incorrect or ambiguous. Added default behaviour and consistency
  suggestions for user- defined classes. Based on patch from Andy Maier.