[FIX] sale_order: set state field track_visibility

sale_order module override state field of sale.oder (sale.sale.py) and forgot to reset the track_visibility, therefore sale orders state changes are no longer tracked once this module installed.
parse_value: interger != float

Wwhen parsing a integer field, do not accept float values. '1' or '1.0' is ok but not '1.1'. (opw 608544)