Using 'warning' and 'return' instead of a fatal at rotate_long if
backuproot doesn't exist. Using a warning ensures that the backup
action can process the other includes and not just exit.

Quoting $exclude and $excludes and avoiding a for loop on $exclude to not expand wildcards in beforehand (upstream #3882)

duplicity 0.6.17 uses paramiko backend.
Thus, it does not support limiting bandwidth anymore.
Let's use trickle to support bandwidth shaping anyway.

... and warn about unsupported options.