Debian packages unconditionally byte-compile .py files on installation and
do not silence errors by design. Therefore, we need a way of shipping these
invalid .py files without a .py extension but ensuring that when we
template them, they end up as .py.

We don't special-case .py files so that the all the TemplateCommand
command-line options (eg. extra_files and extensions) still work entirely
as expected and it may even be useful for other formats too.

Added unapplied migration count and the list of unmigrated apps.

Traceback (most recent call last):
  File "tests\admin_scripts\tests.py", line 646, in test_startapp_unicode_name
    content = f.read()
  File "lib\encodings\cp1252.py", line 23, in decode
    return codecs.charmap_decode(input,self.errors,decoding_table)[0]
UnicodeDecodeError: 'charmap' codec can't decode byte 0x81 in position 46: character maps to <undefined>

Also discouraged its use outside the intended use case.

Thanks Maxime Lorant for the report and Tim Graham for suggesting
the improved comment.

Thanks Tim Graham for the patch

Thanks Luis Del Giudice for the report, and Aymeric Augustin and Markus
Holtermann for the reviews.

Thanks Domas Lapinskas for the report and Tim Graham for the
review.

Dropped the DJANGO_TEST_TEMP_DIR environment variable.

Before this change, proper removal depended on the developer passing
dir=os.environ['DJANGO_TEST_TMP_DIR'] to tempfile functions.

Refs #24324 -- Fixed Python 2 test failures when path to Django source contains non-ASCII characters.

This is a performance optimization and also fixes test errors with the
upcoming merge of contrib tests into tests/. The tests failed on MySQL
because the models with GeometryField were being checked but the
non-GIS MySQL backend didn't know how to handle them.

Kept support for creating models without migrations when running tests
(especially for Django's test suite).

Thanks kabakov.as@gmail.com for the report, and Aymeric Augustin,
Simon Charette for the reviews.

sqlall will be removed in Django 1.9, so now's a good time to remove
its usage where it's not important.

This includes the following improvements:

- The type of the style object is now called 'Style' rather than 'dummy'.
- The new make_style() function allows generating a Style object directly
  from a config string. Before the only way to get a style object was
  through the environ and it also required that the terminal supported
  colors which isn't necessarily the case when testing.
- The output of no_style() is now cached with @lru_cache.
- The output of no_style() now has the same set of attributes as the
  other Style objects. Previously it allowed anything to pass through
  with __getattr__.

Thanks Tim Graham for the review.

Refs #23663.