Allow to set option is_called for setval

[Bartosz Dmytrak]

I just noticed pgAdmin cannot set value of sequence to start with 1 because generates SQL like this:
SELECT setval('"MySchema?"."MySequence?"', 1, true);

it is not possible to set "is_called" option of setval to false.
According to doc ( http://www.postgresql.org/docs/9.1/static/functions-sequence.html):
* "If it is set to false, the next nextval will return exactly the specified value, and sequence advancement commences with the following nextval"*

so, please add checkbox in sequence properties to allow to modify this switch.