Make flip_latitude an enum

Author: lethosor

df.world-data.xml

@@ -461,7 +461,7 @@
         <enum-item/>
         <enum-item/>
     </enum-type>
-    
+
     <enum-type type-name='front_type' base-type='uint16_t'>
         <enum-item name='front_none'/>
         <enum-item name='front_warm'/>
@@ -656,7 +656,12 @@
 -->
         <int32_t name='unk_78'/>
         <int32_t name='moon_phase'/>
-        <int16_t name='flip_latitude' comment='-1 = no poles, 0 = pole on north, 1 = pole on south, 2 = both poles'/>
+        <enum name='flip_latitude' base-type='int16_t'>
+            <enum-item name='None' value='-1'/>
+            <enum-item name='North'/>
+            <enum-item name='South'/>
+            <enum-item name='Both'/>
+        </enum>
         <int16_t name='flip_longitude'/>
         <int16_t name='unk_84'/>
         <int16_t name='unk_86'/>