Both Python 2.7 and Python 3 have the type bytes. On Python 2.7, it is
an alias of str, same as was previously defined in compat.py. Makes the
code slightly more compatible with Python 3 style syntax. Observe:

    $ python2
    >>> bytes
    <type 'str'>

This patch fixes the formatting on INSERT by creating a new
instance of sql.Values to group all the values.

SQL: insert into foo values (1, 'foo'), (2, 'bar'), (3, 'baz')

Before:
insert into foo
values (1,
        'foo'), (2,
                 'bar'), (3,
                          'baz')

After:
insert into foo
values (1, 'foo'),
       (2, 'bar'),
       (3, 'baz')