The `raw_attribute` will be used to mark raw bits, even HTML and LaTeX, and even when `raw_html` and `raw_tex` are enabled, as they are by default. To get the old behavior, disable `raw_attribute` in the writer. Closes #4311.
This fixes a regression in 2.0. Note that extensions can now be individually disabled, e.g. `-f opml-smart-raw_html`. Closes #4164.