[1.7.x] Fixed #13755 -- Added a tip for caching responses that vary on AJAX.

Thanks mila for the suggestion.

Backport of db9a1a0c47 from master
[1.7.x] Fixed #22932: Documented circular dependency issues with swappable user
[1.7.x] Removed non-existent reference to args/kwargs in manager docs.

Backport of 5842d8eba4 from master
[1.7.x] Clarified that LocMemCache is per-process; refs #7639.

Thanks projectgus for the suggestion.

Backport of c37000ab04 from master
[1.7.x] Fixes #22940 -- Show missing module/function when raised.