Message Folder UI issues and crash

[wb8tyw]

The message folder has a popup menu for the messages directory.

This popup menu allows you to "Create" child folders, and for child folders it allows "Delete" "Create" and "Rename".

The popup menu should have better named buttons as it was not obvious that it was creating a subfolder.
Each subfolder is paired with a "ConfigParser" file named a database.

I did not notice that it created a new child folder until I created two of them, which it created with the same display name.
It should not have allowed that to happen.

On attempting to delete the second child folder with the displayed name, an exception was thrown because the base path for the ConfigParser database file no longer existed.