godot: Editor doesn't reload changed resources.

Operating system or device - Godot version: Arch Linux 64bit - Godot 2.1 alpha compiled with b2a4908e9cc802a838a67f92dd66a17d3894c619

Issue description (what happened, and what was expected):

The editor doesn’t reload changed resources generated by ResourceSaver.

Steps to reproduce:

1. Create a resource and save it with ResourceSaver in script (version 1).
2. Open the resource with editor it seems everything is fine.
3. Create another different resource and save it to the same path (version 2).
4. Open the overwrited resource you can see it still be the version 1.
5. Check the resource file with other text editor, it is correct.
6. Reopen the project and open the resource file , it will show version 2

Link to minimal example project (optional but very welcome):

https://drive.google.com/file/d/0B0AolAabr5edbXpEZkVnVXRXRTA/view