Possible candidates to add to the Defaults concept:

tzinfo

We should use Defauts.tzinfo as default instead of UTC … That would mean:

• When a job is created without setting tzinfo explicitly, use Defaults.tzinfo
• When calling JobQueue._put() with a naive when, use when.replace(tzinfo=defaults.tzinfo)
  This would basically not change the current set up, but just put it under the hood
• Probably Message.date and all the friends should also use defaults.tzinfo, so basically every datetime instance occuring in the lib.

Arguments of Filters

• Filters.command: allow commands anywhere in the text or not
• Filters.{user, chat}: allow_empty (only relevant after Allow updating user_ids/usernames of a running filters.user #1757)

How to make it work: We would need to override those attributes on dispatcher.add_handler somehow. that's pretty much the only time, the filters and the dispatcher can see each other …

Dice.emoji

• Only relevant after Api 4.8 #1917. Also discussable, if this really is a good idea, as the emoji attribute of Dice is positional and not optional

ReplyKeyboardMarkup

• resize_keyboard
• one_time_keyboard

Redesign of default_quote

Right now, default_quote get's passed from getting updates through all objects, whose attributes have a Message attribute and is set as attribute in Message. But as the Message.reply_* methods only work with a bot anyway, we could just access Message.bot.defaults.default_quote.

See #1965