File picker: still some issue when creating and uploading new directories and files: refresh is stil buggy

The file picker still does not correctly handle the tree refresh when you are doing certain operations.

For instance I was:

• creating a new directory under an empty virtual site directory
• uploading a file

In order to access to such a file, I add to close the parent directory, reopen it, reopen my newly created direcoty and I could finally see my newly uploaded file.

All trees should by default display the next level. This is clearly not so performance killer and will really help navigation and avoids useless clicks. When uploading a new file, the user should immediately see it in the current directory. Same is true when creating a new directory. There should be no unexpand and reexpand action for such basic operations.