Fixed #20168 - Generalized a PostgreSQL specific database query in the docs.

Thanks Russ for the suggestion.
Fixed #9913 - Clarified User.is_authenticated docs.

Thanks rshea for the draft text.
Fixed #8649 - Documented a caveat about dynamically adjusting formsets.
Fixed #19220 -- Prevented decimals to be displayed in scientific notation

Thanks nebstrebor for the report and antofik for the patch.
Fixed #20167 -- Preserve the traceback of `ImportError`s in `import_by_path`.

Thanks @carljm for the review.