bug#66676: 29.1; Should some aspects of shr rendering be configurable

[Rahguzar]

Dear Emacs developers,

Please find attached 5 patches:

1) The first introduces and uses the options Eli agreed with. These
include options to not fill text, configurable raise properties for
super and subscripts and :ascent property for images. The default values
for these new options do not alter the current behavior.

2) The second introduces an option to allow displaying some images
inline. The default value again preserves the existing behavior.

3) The third patch added an outline-search function and outline-level to
shr.el. These can be set by modes such as eww to provide outline
support.

4) The fourth patch adds these to provide outline support to eww. It has
enables visual-line-mode if shr is configured not to use
visual-line-mode.

5) The fifth patch corrects some misbehavior that I observed but I am
not sure it is the right thing so please feel free to disregard it.
Before inserting a subscript it checks if the subscript in on a newline
and in that case removes the newline. The newlines seem to be coming
from <br> tags which seems to be there to provide vertical alignment of
subscript and superscript if both are present.

Thanks,
Rahguzar

0001-Make-some-aspects-of-shr-rendering-customizable.patch
Description: Text Data

0002-Allow-displaying-images-inline.patch
Description: Text Data

0003-Outline-support-for-shr-rendered-documents.patch
Description: Text Data

0004-Optionally-turn-on-visual-line-mode-outline-support.patch
Description: Text Data

0005-Don-t-insert-subscript-on-a-newline.patch
Description: Text Data