Allow multiple identifiers in OvProductType and OvagentType and allow multiple TEL values in OvcontactType

The same element TEL is used for 'telefoon', 'fax' and 'mobiel' and multiple values of each are allowed according to the specs.

from the v1.0 specs:
"Telefoon, Mobiel en Fax zijn niet verplichte attributen die meerdere keren mogen voorkomen."


added 2013-10-24:
The LocatorDesignator in OsloAddressType should be optional.
This LocatorDesignator is the one from the inspire namespace. It's used for storing 'subadres'. Most addresses don't have a 'subadres'.