==========================Django 1.8.1 release notes==========================*May 1, 2015*Django 1.8.1 fixes several bugs in 1.8 and includes some optimizations in themigrations framework.Bugfixes========* Added support for serializing :class:`~datetime.timedelta` objects inmigrations (:ticket:`24566`).* Restored proper parsing of the :djadmin:`testserver` command's positionalarguments (fixture names) (:ticket:`24571`).* Prevented ``TypeError`` in translation functions ``check_for_language()`` and``get_language_bidi()`` when translations are deactivated (:ticket:`24569`).* Fixed :djadmin:`squashmigrations` command when using:class:`~django.db.migrations.operations.SeparateDatabaseAndState`(:ticket:`24278`).* Stripped microseconds from ``datetime`` values when using an older version ofthe MySQLdb DB API driver as it does not support fractional seconds(:ticket:`24584`).* Fixed a migration crash when altering:class:`~django.db.models.ManyToManyField`\s (:ticket:`24513`).* Fixed a crash with ``QuerySet.update()`` on foreign keys to one-to-one fields(:ticket:`24578`).* Fixed a regression in the model detail view of:mod:`~django.contrib.admindocs` when a model has a reverse foreign keyrelation (:ticket:`24624`).* Prevented arbitrary file inclusions in :mod:`~django.contrib.admindocs`(:ticket:`24625`).* Fixed a crash with ``QuerySet.update()`` on foreign keys to instances with``uuid`` primary keys (:ticket:`24611`).* Fixed database introspection with SQLite 3.8.9 (released April 8, 2015)(:ticket:`24637`).* Updated ``urlpatterns`` examples generated by :djadmin:`startproject` toremove usage of referencing views by dotted path in``django.conf.urls.url()`` which is deprecated in Django 1.8(:ticket:`24635`).* Fixed queries where an expression was referenced in ``order_by()``, but wasn'tpart of the select clause. An example query is``qs.annotate(foo=F('field')).values('pk').order_by('foo'))`` (:ticket:`24615`).* Fixed a database table name quoting regression (:ticket:`24605`).* Prevented the loss of ``null``/``not null`` column properties during fieldalteration of MySQL databases (:ticket:`24595`).* Fixed JavaScript path of ``contrib.admin``’s related field widget when usingalternate static file storages (:ticket:`24655`).* Fixed a migration crash when adding new relations to models(:ticket:`24573`).* Fixed a migration crash when applying migrations with model managers onPython 3 that were generated on Python 2 (:ticket:`24701`).* Restored the ability to use iterators as queryset filter arguments(:ticket:`24719`).* Fixed a migration crash when renaming the target model of a many-to-manyrelation (:ticket:`24725`).* Removed flushing of the test database with :option:`test --keepdb`, whichprevented apps with data migrations from using the option (:ticket:`24729`).* Fixed ``makemessages`` crash in some locales (:ticket:`23271`).* Fixed help text positioning of ``contrib.admin`` fields that use the``ModelAdmin.filter_horizontal`` and ``filter_vertical`` options(:ticket:`24676`).* Fixed ``AttributeError: function 'GDALAllRegister' not found`` error wheninitializing ``contrib.gis`` on Windows.Optimizations=============* Changed ``ModelState`` to deepcopy fields instead of deconstructing andreconstructing (:ticket:`24591`). This speeds up the rendering of modelstates and reduces memory usage when running :djadmin:`manage.py migrate<migrate>` (although other changes in this release may negate any performancebenefits).