Make signature cache store CPubKeys

src/allocators.h

@@ -176,6 +176,10 @@ private:
     {}
 };
 
+//
+// Functions for directly locking/unlocking memory objects.
+// Intended for non-dynamically allocated structures.
+//
 template<typename T> void LockObject(const T &t) {
     LockedPageManager::instance.LockRange((void*)(&t), sizeof(T));
 }