Revert "unordered_map value type, is of std::pair<const Key, T>, hence a copy from const Key to Key is never shallow."

This reverts commit 6985c8f64c.

encfs/Context.cpp

@@ -127,6 +127,14 @@ void EncFS_Context::eraseNode(const char *path, FileNode *pl) {
 
   it->second.pop_front();
 
+  // if no more references to this file, remove the record all together
+  if (it->second.empty()) {
+    // attempts to make use of shallow copy to clear memory used to hold
+    // unencrypted filenames.. not sure this does any good..
+    std::string storedName = it->first;
+    openFiles.erase(it);
+    storedName.assign(storedName.length(), '\0');
+  }
 }
 
 }  // namespace encfs