May 18 changes #617

Payment:

• New updates: shipping_query and pre_checkout_query
• New message content fields: invoice and successful_payment
• New bot methods: sendInvoice, answerShippingQuery, and answerPreCheckoutQuery
• New button type: pay (new boolean argument for InlineKeyBoardButton)

Weird rounded video messages

• New bot method: sendVideoNote
• New Message field: video_note
• New ChatActions: record_video_note or upload_video_note
• VideoNote class

i18n

• New User field: language_code
  Note that the documentation uses "may" wording here... we should do some research as to when.

Admin power???

• Remove warning from delete_message

Minor stuff

• Rename new_chat_member to new_chat_members
• New fields gif_duration (InlineQueryResultGif) and mpeg4_duration (InlineQueryResultMpeg4Gif)