Avoid placing notes twice
Support reStructuredText compound paragraphs
Support reStructuredText topic
Support reStructuredText rubric
Basic support for reStructuredText sidebar

- sidebar contents are rendered in a frame with background
- but as a regular flowable, not to the side
Basic support for all reStructuredText admonitions

They cannot yet be styled individually.
Allow for individual styling of the different admonition types

- set the admonition_type attribute on the Framed instances
- a single style can be associated with several Selectors
- ClassSelector: don't fail if a Styled doesn't have an attribute
A reStructuredText reference is a nested element
reStructuredText problematic elements can also be empty
Bugfix: special characters should not be grouped
Don't hyphenate literal text
A style for level 3 headings
reStructuredText: handle dual-purpose body/inline elements
Distinguish between Flowable/StyledText-yielding rST elements

- the build_flowable and build_styled_text methods make things explicit
- some elements are both BodyElement and InlineElement (e.g. Reference)
- for inline elements, build_styled_text is always called
- eliminate NestedElement; process_content needs to be available to both
BodyElement and InlineElement
Handle text filtering in the frontend
fixup! Distinguish between Flowable/StyledText-yielding rST elements

- the build_flowable and build_styled_text methods make things explicit
- some elements are both BodyElement and InlineElement (e.g. Reference)
- for inline elements, build_styled_text is always called
- eliminate NestedElement; process_content needs to be available to both
BodyElement and InlineElement