Fixed #8408 -- Added ModelAdmin.show_full_result_count to avoid COUNT() query.

Thanks lidaobing for the suggestion.
Fixed #23460 -- Added literal `%s` support to extra() QuerySets.
Fixed #23561 -- Corrected a security doc example that requires an unquoted HTML attribute.

Thanks "djbug" for the report.
How many is two?
Fixed #23560 -- Fixed MigrationWrite to handle builtin types without imports.

Thanks Tim Graham for the review.
Silenced some deprecation warnings in contrib.sitemaps; refs #22384.
Fixed #22738 -- Abstracted boolean field type introspection

Thanks maxi for the report, Shai Berger for his help with the patch
and Tim Graham for the review.
Fixed #22738 -- made finer distinctions for when Boolean is not detected on Oracle

Thanks Claude Paroz for partial fix and Simon Charrette for review
Fixed git blunder, refs #22738
Updated comment about Python issue
Fixed #23436 -- Made BASE_DIR absolute in settings template.

This ensures consistency between Python 3.4+ and earlier versions.

Thanks Harry Percival for the report.
Replaced set([foo, ...]) by {foo, ...} literals. Refs PR 3282.

Thanks Collin Anderson for the review.