Added more details about the various serialization formats.
Fixed the usage of the deprecated assertEquals.
Merge pull request #815 from zerok/tickets/11971

Fixed #11971 -- Documented the serialization formats
Fixed #19896 -- Committed after clearing cache in the database.
Removing unneeded tearDown code.
Add sqldropindexes to manage

Change patch from https://code.djangoproject.com/ticket/5568
to work on modern Django.
Add special case for MySQL which has different syntax for DROP INDEX.
Add unit tests for the new functionality.
Revert "fixes #19263" - Fails if not SQLite

This reverts commit 2b76f19f2b89ac96bae2a169d71b23553c8101c7.
Made changes asked in review by HonzaKral

Add documentation for new command in django-admin.
Merge pull request #817 from rybaktomasz/ticket_5568

Fixes #5568 -- DROP INDEX subcommand
Fixed a few ResourceWarnings.
Fixed #16302 -- Ensure contrib.comments is IPv6 capable

Changed the ip_address field for Comment to GenericIPAddressField. Added
instructions to the release notes on how to update the schema of existing
databases.