Create a library backup whenever the library is reinstalled (upgrades, downgrades, overwrites)

[jefflester]

Whenever the Minitrino library is installed over an existing library, a backup of lib/* contents should be placed in the /tmp/ directory, and an informational log should be shown to the user.

For example:

minitrino lib-install

[i]  The Minitrino library at {user_home}/.minitrino/lib will be overwritten. Continue? [Y/N]: Y
[i]  A backup of the previous library has been stashed in /tmp/minitrino-lib-bkp-{random_id}.tar.gz

Adding this logic removes any worry about libraries with customized modules being accidentally overridden.

The first log message above should be updated from:

The Minitrino library at {user_home}/.minitrino/lib will be overwritten. Continue? [Y/N]: Y

To:

The Minitrino library at {user_home}/.minitrino/lib will be overwritten and a backup will be placed in /tmp/. Continue? [Y/N]: Y

The second log does not presently exist. A random ID should be attached to the resulting filename so that there is no limit on how many individual backups can exist in the /tmp/ directory at any given time.