[Location] - allow multiple <name> elements

[MatthiasArnold]

The VRA schema allows multiple names within a location. these may be of the same or a different type. Example <name type="corporate"> for a museum's name and <name type="geographic"> for the city it located in.

cf. #296

Example from http://www.loc.gov/standards/vracore/VRA_Core4_Element_Description.pdf#15 :

<locationSet>
    <display> Musée du Louvre (Paris, FR) Inv. MR 299; discovered Milos (GR)</display>`
    <location type="repository">
        <name type="corporate" xml:lang="fr">Musée du Louvre</name>
        <refid type="accession">Inv. MR 299</refid>
        <name type="geographic" vocab="TGN" refid="7008038" extent="inhabited place">Paris</name>
        <name type="geographic" vocab="TGN" refid="1000070" extent="nation">France</name>
    </location>
    <location type="discovery">
        <name type="geographic" vocab="TGN" refid="7010922">Milos, Nisos</name>
        <name type="geographic" vocab="TGN" refid="1000074">Greece</name>
    </location>
</locationSet>

[SimonGruening]

cf. #344