Python-telegram-bot

- Add support for ``User.language_code``
- Fix ``Message.text_html`` and ``Message.text_markdown`` for messages with emoji

- Add support for Bot API 2.3.1
- Add support for ``deleteMessage`` API method
- New, simpler API for ``JobQueue`` - https://github.com/python-telegram-bot/python-telegram-bot/pull/484
- Download files into file-like objects - https://github.com/python-telegram-bot/python-telegram-bot/pull/459
- Use vendor ``urllib3`` to address issues with timeouts
- The default timeout for messages is now 5 seconds. For sending media, the default timeout is now 20 seconds.
- String attributes that are not set are now ``None`` by default, instead of empty strings
- Add ``text_markdown`` and ``text_html`` properties to ``Message`` - https://github.com/python-telegram-bot/python-telegram-bot/pull/507
- Add support for Socks5 proxy - https://github.com/python-telegram-bot/python-telegram-bot/pull/518
- Add support for filters in ``CommandHandler`` - https://github.com/python-telegram-bot/python-telegram-bot/pull/536
- Add the ability to invert (not) filters - https://github.com/python-telegram-bot/python-telegram-bot/pull/552
- Add ``Filters.group`` and ``Filters.private``
- Compatibility with GAE via ``urllib3.contrib`` package - https://github.com/python-telegram-bot/python-telegram-bot/pull/583
- Add equality rich comparision operators to telegram objects - https://github.com/python-telegram-bot/python-telegram-bot/pull/604
- Several bugfixes and other improvements
- Remove some deprecated code

Hotfix release due to bug introduced by urllib3 version 1.21

- Implement API changes of November 21st (Bot API 2.3)
- `JobQueue` now supports `datetime.timedelta` in addition to seconds
- `JobQueue` now supports running jobs only on certain days
- New `Filters.reply` filter
- Bugfix for `Message.edit_reply_markup`
- Other bugfixes

- Implement API changes of October 3rd (games update)
- Add `Message.edit_*` methods
- Filters for the `MessageHandler` can now be combined using bitwise operators (`& and |`)
- Add a way to save user- and chat-related data temporarily
- Other bugfixes and improvements

- Fix documentation builds on readthedocs