Experimental: do not disable south migrations

Ref: https://github.com/pelme/pytest_django/issues/128
Fix south integration with `--create-db`

This requires to monkey-patch `south.hacks.django_1_0.SkipFlushCommand`,
which has a bug that prevents any initial data to be installed.

South issue: http://south.aeracode.org/ticket/1395#comment:3

Fixes https://github.com/pelme/pytest_django/pull/22

Django code reference for 1.6, from
django-1.6.x/django/db/backends/creation.py(339)create_test_db():

    # Report syncdb messages at one level lower than that requested.
    # This ensures we don't get flooded with messages during testing
    # (unless you really ask to be flooded)
    call_command('syncdb',
        verbosity=max(verbosity - 1, 0),
        interactive=False,
        database=self.connection.alias,
        load_initial_data=False)

    # We need to then do a flush to ensure that any data installed by
    # custom SQL has been removed. The only test data should come from
    # test fixtures, or autogenerated from post_syncdb triggers.
    # This has the side effect of loading initial data (which was
    # intentionally skipped in the syncdb).
    call_command('flush',
        verbosity=max(verbosity - 1, 0),
        interactive=False,
        database=self.connection.alias)
Do not create empty files with SQLite ':memory:' with `django_testdir`

 - Keep ':memory:' for DB_NAME and TEST_DB_NAME with SQLite in-memory DB.
 - Skip `create_empty_production_database` with DB_NAME == ':memory:'.
Merge pull request #129 from blueyed/do-not-disable-south

Handle south migrations
Remove unnecessary assignment in conftest
Merge branch 'fix-sqlite-memory-dbname'

Conflicts:
	tests/conftest.py
tests: use 1.7c2 for Django 1.7
Various PEP8 & typos fixes. Update setup.py
Fixes, according to @blueyed comments
Merge pull request #143 from Stranger6667/cleanup

Various PEP8 & typos fixes. Update setup.py
Remove support for having settings within test directories
Call django.setup() directly after configuring settings
Added changelog entry for #119, #134
Added share/ to gitignore
Fix README, drop python 2.5 related code
Merge pull request #147 from Stranger6667/fix-doc

Fix README, drop python 2.5 related code
Add new fixtures: admin_user, django_user_model, django_username_field

This factors the admin user out of the `admin_client` fixture and
provides it separately.

It also adds the `django_user_model` and `django_username_field`
fixtures, which have been factored out when writing a test for the
`admin_user` fixture.
Rephrase handling of TEST_DB_NAME with ':memory:'
Merge the test clients environ setup from Django master

I have noticed and compared it because of flake8 issues, and the only
non-whitespace changes are the addition of `str()` and `b''` wrappers.
Merge pull request #152 from blueyed/merge-django-test-client

Merge client environ setup from Django master