fix remaining issues with theme refactor branch

src/core/Json.cpp

@@ -13,7 +13,7 @@ namespace Json
         size_t fileLength = (size_t)fs.GetLength();
         if (fileLength > maxSize)
         {
-            throw IOException("Language file too large.");
+            throw IOException("Json file too large.");
         }
 
         utf8 * fileData = Memory::Allocate<utf8>(fileLength + 1);

src/core/List.hpp

@@ -47,7 +47,7 @@ public:
     void Insert(T item, size_t index)
     {
         Guard::ArgumentInRange(index, (size_t)0, this->size());
-        this->insert()
+        this->insert(this->begin() + index, item);
     }
 
     bool Remove(T item)