Pop up error message if user try to create duplicated note

Hi,

I am using 0.9.0 which has zpln as the new supported note format. However, I have a couple of problems:

1- If everyone at the same time creates a note with the same name, even though there is a unique ID after the name on HDFS, it still messes up all the permissions! An empty note I created just needs to wait a few seconds and then it says I don't have enough permission to view it. 

2- It becomes impossible to remove these notes! It says it doesn't exist!