write visual and collision name to xml

[briansoe66]

write visual and collision name to xml

[SuperJappie08]

@briansoe66, The XSD for the visual element should then be updated as well, as it currently does not list the name attribute.

urdfdom/xsd/urdf.xsd

Lines 123 to 133 in 3f6bf9a

	<!-- visual node type -->
	<xs:complexType name="visual">
	<xs:sequence>
	<xs:element name="origin"
	type="pose" minOccurs="0" maxOccurs="1" />
	<xs:element name="geometry"
	type="geometry" minOccurs="1" maxOccurs="1" />
	<xs:element name="material"
	type="material" minOccurs="0" maxOccurs="1" />
	</xs:sequence>
	</xs:complexType>

It already is described for the collision element.

urdfdom/xsd/urdf.xsd

Lines 135 to 147 in 3f6bf9a

	<!-- collision node type -->
	<xs:complexType name="collision">
	<xs:sequence>
	<xs:element name="origin"
	type="pose" minOccurs="0" maxOccurs="1" />
	<xs:element name="geometry"
	type="geometry" minOccurs="1" maxOccurs="1" />
	<xs:element name="verbose"
	type="verbose" minOccurs="0" maxOccurs="1" />
	</xs:sequence>
	<!-- FIXME: used but not documented -->
	<xs:attribute name="name" type="xs:string" />
	</xs:complexType>