Several little tweaks and fixes

- Fix some uninitialized fields getting populated with random data
- Fix identity of last edited town and outdoor section not being saved
- Fix editor sometimes saving to application directory instead of overwriting the loaded scenario
- Fix town specials being saved to outdoors list and vice versa
- Fix right-most column of map not being loaded properly
- Fix town entry node for start town being called after the first turn of the scenario
- Add option to call a special node at startup (right after the intro dialog)

rsrc/schemas/scenario.xsd

@@ -181,6 +181,7 @@
 				<xs:element name="num-towns" type="xs:integer"/>
 				<xs:element name="out-width" type="xs:integer"/>
 				<xs:element name="out-height" type="xs:integer"/>
+				<xs:element name="on-init" type="xs:integer"/>
 				<xs:element name="start-town" type="xs:integer"/>
 				<xs:element name="town-start">
 					<xs:complexType>