Prefer the earliest eponymous nodes in skeletons (bug #3842)

CHANGELOG.md

@@ -1,6 +1,7 @@
 0.49.0
 ------
 
+    Bug #3842: Body part skeletons override the main skeleton
     Bug #4127: Weapon animation looks choppy
     Bug #4204: Dead slaughterfish doesn't float to water surface after loading saved game
     Bug #4610: Casting a Bound Weapon spell cancels the casting animation by equipping the weapon prematurely

components/sceneutil/skeleton.cpp

@@ -23,7 +23,7 @@ namespace SceneUtil
         void apply(osg::MatrixTransform& node) override
         {
             mPath.push_back(&node);
-            mCache[Misc::StringUtils::lowerCase(node.getName())] = mPath;
+            mCache.emplace(Misc::StringUtils::lowerCase(node.getName()), mPath);
             traverse(node);
             mPath.pop_back();
         }