Allow TextBoxWidget new text direction/lang parameters to be
set on upper widgets, and propagate them all the way to it
(ScrollTextWidget, InputText, InputDialog, TextViewer).
Use specific non-default ones in some specific cases:
- Force LTR text direction when showing HTML and CSS, and
configuration files (in some plugins).
- Use Wikipedia server language and text direction when
showing an article.
- Use auto with Dictionary results, as we don't know the
dictionary language, and they may contain mixed content.
- Force LTR when showing some paths (still needs more of them)
TextEditor plugin: add 2 new options "Auto paragraph direction"
and "Force paragraph direction LTR".
Footnotes popup: grab HTML direction, and forward it
to MuPDF for proper display.
