- Fix hold callback name
- Add options to handle long titles (truncated by default):
"title_multines" and "title_shrink_font_to_fit" (allowing
setTitle() with them makes the code a bit more complex).
- Add options to set bottom line color and horizontal padding.
- Use an added close.svg (based on exit.svg, tweaked to have
similar size and baseline as other icons) for close button.
IconButton:
- handle hold/hold_release similar to Button.
- new option allow_flash to allow disabling flashing.
Existing widgets building their own title bar with help
of CloseButton should progressively be updated to use
this, for clarity, consistency, and less code duplication.
