Fixed #21196 -- Removed index on test field causing MySQL specific warning.
Fixed #23684 -- Used correct package name for Pillow in Error hint.
Fixed a typo in urlencode documentation.
Merge pull request #3390 from wrwrwr/fix/urlencode-ref-typo

Fixed a typo in urlencode documentation.
Prevented syncdb from calling system checks multiple times. Refs #23650.
Renamed skip_validation into skip_checks as the former is now deprecated.
Made the ping_google command override BaseCommand.handle() rather than execute().

Overriding execute() bypasses the system check framework among other things.
Moved a test case that caused deprecation warnings.

`cache.tests.TestEtagWithAdmin` loaded views from the `admin_views` test
package. This is problematic because when the `cache` test package is
run in isolation, `admin_views` isn't in INSTALLED_APPS, and therefore
loading its models isn't allowed since the app loading refactor.
Fixed #20609 -- Added instructions for using AnonymousUser with RequestFactory.
Fixed #23685 -- Made call_command skip checks by default

Thanks Loic Bistuer for the report/review and Tim Graham for the
review.
Revert "Fixed #23650 -- Prevented migrate from calling checks 3 times"

This reverts commit 8d6e1afe0be0570253a508f43e2ef89ae640984e.
call_command now always set skip_checks to True (tested in
user_commands).
Removed redundant skip_checks option for call_command
Fixed #23692 -- Removed alpha/beta/rc release notes.
Fixed #23668 -- Changed make_aware() and make_naive() to use the current timezone by default

Thanks Aymeric Augustin for review.
Fixed #23629 -- Allowed autodetector to detect changes in Meta.db_table.

Thanks Naddiseo for reporting.
Clarify that HTTP Accept-Language header is case-insensitive.
Fixed #23679 -- Fixed null introspection for char/text fields

Thanks Paul Dejean for the report.
Fixed #20221 -- Allowed some functions that use mark_safe() to result in SafeText.

Thanks Baptiste Mispelon for the report.
Fixed #23688 -- Updated cached_property to preserve docstring of original function
Fix SettingsCustomLoggingTest on Windows when path contains \u