Fixed #20493 -- Added a warning that objects may not be picklable across Django versions

Thanks cataliniacob for the suggestion and review.
Fixed #16965 -- Clarified Formset can_delete docs.

Thanks gregcorey@ for the suggestion.
Fixed #19695 -- Retitle "Form Media" to "Form Assets".
Fixed #18944 -- Documented PasswordResetForm's from_email argument as a backwards incompatible change for 1.3

Thanks DrMeers for the report.
Fixed last_executed_query test failure on Oracle
Fixed #17339 -- Factor out has_result into database backend.

Thanks jonash.
Fixed #18261 -- Clarified 'project root directory'
Partial revert of commit 2bf403ecbd95

Homework: write 100 times geoapp is not geogapp.
Fixed #19196 -- Added test/requirements