Added "suffix" paramater, to allow eg forcing a particular country.

Added "suffix" paramater, to allow eg forcing a particular country.

For example --

    street = models.CharField(max_length=255, blank=True)
    suburb = models.CharField(max_length=100, blank=True, default='Sydney')
    state = AUStateField(blank=True, default='NSW')
    postcode = AUPostCodeField(blank=True, default='2000')
    point = LocationField(null=True, blank=True, based_fields=[street, suburb, state, postcode], 
                zoom=13, suffix='Australia')