Add a user-defined name to vehicle definitions.

This also adds partial support for a custom vehicle graphic.

rsrc/schemas/scenario.xsd

@@ -289,6 +289,23 @@
 					</xs:simpleContent>
 				</xs:complexType>
 			</xs:element>
+			<xs:element name="vehicle" minOccurs="0" maxOccurs="unbounded">
+				<xs:complexType>
+					<xs:attribute name="type">
+						<xs:simpleType>
+							<xs:restriction base="xs:string">
+								<xs:enumeration value="boat"/>
+								<xs:enumeration value="horse"/>
+							</xs:restriction>
+						</xs:simpleType>
+					</xs:attribute>
+					<xs:attribute name="id" type="xs:integer"/>
+					<xs:sequence>
+						<xs:element name="name" type="xs:string"/>
+						<xs:element name="pic" type="xs:integer"/>
+					</xs:sequence>
+				</xs:complexType>
+			</xs:element>
 		</xs:sequence>
 	</xs:complexType>
 	<xs:complexType name="editorData">