Added elephant & ankheg models

Added elephant & ankheg models & portraits  Imported pnp creature UTCs over from NWNDS for ankhegs, air elementals, scorpions, cheetahs & invisible stalkers. Setup burrower AI or testing.  Full compile.

_module/are/emptyseacave.are.json

@@ -14,7 +14,7 @@
   },
   "Comments": {
     "type": "cexostring",
-    "value": "Empty Sea Cave"
+    "value": "Sea Coast Road: Empty Cave"
   },
   "Creator_ID": {
     "type": "int",
@@ -87,7 +87,7 @@
   "Name": {
     "type": "cexolocstring",
     "value": {
-      "0": "Empty Sea Cave"
+      "0": "Sea Coast Road: Empty Cave"
     }
   },
   "NoRest": {
@@ -148,7 +148,7 @@
   },
   "Tag": {
     "type": "cexostring",
-    "value": "EmptySeaCave"
+    "value": "SCR_EMPTYCAVE"
   },
   "Tile_List": {
     "type": "list",
@@ -849,7 +849,7 @@
   },
   "Version": {
     "type": "dword",
-    "value": 7
+    "value": 8
   },
   "Width": {
     "type": "int",