Fixed #2166 - Use "manage.py dbshell" as the portable way to pipe commands to

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If you don't mind clearing data, just pipe the output of the appropriate

``django-admin.py sqlreset`` command into your database's command-line utility.

``manage.py sqlreset`` command into your database's command-line utility.

For example::

    django-admin.py sqlreset appname | psql dbname

    manage.py sqlreset appname | manage.py dbshell

That "psql" assumes you're using PostgreSQL. If you're using MySQL, use the

appropriate command-line utility, ``mysql``.

``django-admin.py sqlreset`` outputs SQL that clears the app's database

``manage.py sqlreset`` outputs SQL that clears the app's database

table(s) and creates new ones. The above command uses a Unix pipe to send the

SQL directly to the PostgreSQL command-line utility, which accepts SQL as

input.

SQL directly to the database command-line utility, which accepts SQL as

input (``manage.py dbshell`` will launch the appropriate tool for the database

configured in ``settings.py``).

If you do care about deleting data, you'll have to execute the ``ALTER TABLE``

statements manually in your database. That's the way we've always done it,