py-prompt_toolkit2: updated to 3.0.3

3.0.3:
New features:
- Improved support for "dumb" terminals.
- Added support for new keys (vt100 ANSI sequences): Alt +
  home/end/page-up/page-down/insert.
- Better performance for the "regular languages compiler". Generate fewer and
  better regular expressions. This should improve the start-up time for
  applications using this feature.
- Better detection of default color depth.
- Improved the progress bar:
  * Set "time left" to 0 when done or stopped.
  * Added `ProgressBarCounter.stopped`.
- Accept callables for `scroll_offset`, `min_brightness` and `max_brightness`.
- Added `always_prefer_tty` parameters to `create_input()` and `create_output()`.
- Create a new event loop in `Application.run()` if `get_event_loop()` raises
  `Runtimeerror`.

Fixes:
- Correct cancellation of flush timers for input. (Fixes resource leak where
  too many useless coroutines were created.)
- Improved the Win32 input event loop. This fixes a bug where the
  prompt_toolkit application is stopped by something other than user input. (In
  that case, the application would hang, waiting for input.) This also fixes a
  `RuntimeError` in the progress bar code.
- Fixed `line-number.current` style. (was `current-line-number`.)
- Handle situation where stdout is no longer a tty (fix bug in `get_size`).
- Fix parsing of true color in ANSI strings.
- Ignore `invalidate()` if the application is not running.

(adam)