Instead of using the depth configured in Book map, start
with max depth, and allow decreasing (and reseting when
at 0) with long-press on the (i) top left icon.
- 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.
- Book map: shows a map of content, including TOC,
boomarks, read pages, non-linear flows...
- Page browser: shows thumbnails of pages.
- ReaderThumbnail: new Reader module that provides
a service for generating thumbnails of book pages.
It makes available these 2 new fullscreen widgets.
- ReaderBookmark, ReaderLink, Statistics: add methods
to return new views of bookmarks, previous locations
and read pages, that are needed by BookMapWidget.
- ReaderToc: compute TOC max_depth.
- ReaderBookmark, ReaderHighlight: send events on
bookmark add/update/remove so thumbnails of the
pages impacted can be trashed.
