Added a db_type() method to the database Field class. This is a hook for calculating the database column type for a given Field. Also converted all management.py CREATE TABLE statements to use db_type(), which made that code cleaner. The Field.get_internal_type() hook still exists, but we should consider removing it at some point, because db_type() is more general. Also added docs -- the beginnings of docs on how to create custom database Field classes. This is backwards-compatible.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@5725 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/backends/mysql_old/creation.py

@@ -16,7 +16,6 @@ DATA_TYPES = {
     'ImageField':        'varchar(100)',
     'IntegerField':      'integer',
     'IPAddressField':    'char(15)',
-    'ManyToManyField':   None,
     'NullBooleanField':  'bool',
     'OneToOneField':     'integer',
     'PhoneNumberField':  'varchar(20)',