[Add] Warn if outfit isn't found.

dat/start.xml

@@ -1,7 +1,7 @@
 <Start>
 <name>Dark Tides</name>
 <player>
-<ship>Goddard</ship>
+<ship>Lancelot</ship>
 <credits>
 <low>500000</low>
 <high>1500000</high>

src/outfit.c

@@ -43,6 +43,8 @@ Outfit* outfit_get(const char* name) {
   for(i = 0; i < outfit_nstack; i++)
     if(strcmp(name, outfit_stack[i].name)==0)
       return &outfit_stack[i];
+
+  WARN("Outfit '%s' not found in stack.", name);
   return NULL;
 }