Fixed #22142 -- Documented PostGIS 2 database creation during tests
Fixed docs typos.
Fixed #22071 -- Added a warning regarding override_settings and aliasing.

Thanks EvilDMP for the suggestion.
Fixed #12670 -- Added a note about permissions of files stored in FILE_UPLOAD_TEMP_DIR.

Thanks simon29 for the suggestion.
Removed a nonexistent link in the docs.
Fixed #22145 -- Clarified docs on Field.blank and Field.null options.

Thanks skipjack at peru.com for the suggestion.
Fixed bad grammar in a comment.