Detect if babette is run on encrypted Linux home folder

[richelbilderbeek]

Some Linux distro's (e.g. Lubuntu) allow the option to have an encrypted home folder. babette will fail when running from such a setup, as the temporary files are different.

It would help out the users to warn them.

[richelbilderbeek]

From https://askubuntu.com/a/146512:

ls -A /home

There should be a .ecryptfs folder, if you have encryption of your home folder.