python-btrfs v5, Jan 14 2017
  * Revamp and fix loading of extent backreferences.
  * Explode when detecting a non x86_64 arch.
  * Add a crc32c implementation and example script to create
    a dir_item offset hash.

python-btrfs v4, Dec 18 2016
  * Bump/inverse versioning, there will never be a v1.0, just keep
    developing and releasing. \:D/
  * IOCTLs: LOGICAL_INO
  * New datastructures: InodeItem, RootItem, DiskKey, TimeSpec
  * Add all constants to pretty print tree keys
  * Behaviour change: don't load extent refs by default
  * Keep transid value when retrieving a BlockGroupItem
  * Known issue:
    - SHARED_BLOCK_REF and TREE_BLOCK_REF are missing in extent refs

python-btrfs 0.3, Nov 15 2016
  * Showing the contents of metadata block groups
  * Renamed datastructures: DevItem, BlockGroupItem, ExtentItem
  * New datastructures: TreeBlockInfo, MetaDataItem, TreeBlockRef,
    SharedBlockRef, DevStats
  * IOCTLs: IOC_GET_DEV_STATS
  * Fixes:
    - Python 3 compatibility, again

python-btrfs 0.2, Jun 28 2016
  * Datastructures: DevExtent
  * Python 3 compatibility
  * Utils: lookup total filesystem usage (incl. unallocatable space)
  * Example nagios nrpe monitoring plugin
  * Fixes:
    - Optimize block group search

python-btrfs 0.1, Jun 21 2016
  * IOCTLs: IOC_SPACE_INFO, IOC_TREE_SEARCH, IOC_FS_INFO, IOC_DEV_INFO
  * Datastructures: Device (dev_item), Chunk, Stripe, BlockGroup,
    Extent, ExtentDataRef, SharedDataRef
  * btrfs.FileSystem main entry point for usage
  * Handing of the search Key (objectid, type, offset)
  * Utils: pretty printing amounts of bytes and block group /
    chunk types and profiles (like, MetaData, RAID1 etc...),
    determine wasted (unallocatable) space for RAID0, RAID1
  * Example snippets using all functionality
  * Example munin monitoring plugin
