Add a simple script for running rsync_tmbackup.sh from cron.
Fix spaces in filenames.
Sort fn_find_backups newest first.
Drop some single-use variables.
Simpler absolute paths.
Redundant.
Simplify symlink creation.
Define trivial functions on one line only.
Determine $APPNAME programmatically.
Use bash : noop for efficiency.
Use -n and -z for easier string emptiness checks.
Extra quotes everywhere!
Rebase on @laurent22/master.
Even more quotes.
Yet more quotes!
Restoring `$(basename -- "$DEST")`

In case the destination is later on generated in a different way,
also makes the code and intention more explicit.