Feature Request - Encrypt Backups

Since this can use 7-Zip to compress the backups, it would be nice to also have the ability to encrypt them with that. This can probably be done by tweaking the command line parameters in the compression box in options, but that's problematic both due to not being user-friendly and, more importantly, it would leave the password there to be seen.

Start by reviewing the compression box in Options and how CloneApp invokes 7-Zip for backups. Define how encryption and password entry should work without leaving the password visible; done means backups can be encrypted through the interface without exposing the password.

Written by the indexing model from the issue text.