[1.5.x] Fixed #19729 -- Removed leftover refactoring helper variables.

Thanks chrismedrela for the report.

Refs #6262, 44b9076 and 4d94c0c.

826d9de00e74a53d7cc65fcb2aaa5ccdf33674ab from master.
[1.5.x] Typo in i18n docs.

112c6e987dbe789c8eb1889852f6056131c8d4d6 from master.
[1.5.x] Mention backward relationships in aggregate docs.

Thanks Anssi and Marc Tamlyn for reviewing.

Fixes #19803.

0560bfb705687c831e2769b1202706e2ceb1f7a7 from master.
[1.5.x] Fix filtering during collection of paths in setup.py

Thanks Marek Brzóska for the report.

f179a5198e05e1be8ba8be87c1f0e1a8924cf005 from master.