coverity findings: add missing initialization.

code/SceneCombiner.cpp

@@ -492,7 +492,7 @@ void SceneCombiner::MergeScenes(aiScene** _dest, aiScene* master,
         // To offset or not to offset, this is the question
         if (n != (int)duplicates[n])
         {
-            // Get full scenegraph copy
+            // Get full scene-graph copy
             Copy( &node, (*cur)->mRootNode );
             OffsetNodeMeshIndices(node,offset[duplicates[n]]);
 

code/glTFImporter.cpp

@@ -78,13 +78,14 @@ static const aiImporterDesc desc = {
 
 glTFImporter::glTFImporter() 
 : BaseImporter()
-{
-
+, meshOffsets()
+, embeddedTexIdxs()
+, mScene( NULL ) {
+    // empty
 }
 
-glTFImporter::~glTFImporter()
-{
-
+glTFImporter::~glTFImporter() {
+    // empty
 }
 
 const aiImporterDesc* glTFImporter::GetInfo() const