* btrbk-0.10
  - initial revision

* btrbk-0.11
  - added option -p (preserve backups)
  - added optional subvolume argument for run/dryrun actions, for
    explicit selection of subvolumes to be processed
  - bugfixes

* btrbk-0.12
  - cleaner and more generic parsing of btrfs subvolume list
  - bugfix: subvolumes are also allowed for "snapshot_dir" (fixes
    issues #1, #2)

* btrbk-0.13
  - bugfix: allow '@' character for subvolume names (blocker for
    ubuntu users, since ubuntu prefixes all subvolumes with '@' in its
    subvolume layout). Fixes issue #3

* btrbk-0.14
  - bugfix: correctly handle empty target subvolumes (blocker for all
    new users). Fixes issue #4

* btrbk-current
  - added configuration option "btrfs_progs_compat", to be enabled if
    using btrfs-progs < 3.17. Fixes issue #6
  - added configuration option "resume_missing", for automatic resume
    of missing backups
  - removed configuration option "receive_log" in favor of printing
    errors from "btrfs receive"
  - bugfix: show correct exit code on external command failure
  - bugfix: no crash if "commit_delete" option is set to "no"