* upstream/develop: (37 commits)
  Fix constraint error reported by @jacklul Close  #289
  Small typos and comment corrections.
  Simplify isAdmin method.
  Minor fixes.
  Various little code and comment updates.
  Refactor JSON entities array string generation. Add new helper method entitiesArrayToJson.
  Tidy up selectChats method.
  Tidy up insertEditedMessageRequest method.
  Tidy up insertMessageRequest method.
  Tidy up insertCallbackQueryRequest method.
  Tidy up insertChosenInlineResultRequest method.
  Tidy up insertInlineQueryRequest method.
  Tidy up insertChat method.
  Tidy up insertUser method.
  Tidy up insertRequest method.
  Tidy up insertTelegramUpdate method.
  DRY up getTimestamp method.
  Tidy up selectMessages method.
  Tidy up selectTelegramUpdate method.
  Simplify defineTables method.
  ...