=== unicorn 5.1.0 - rack is optional, again / 2016-04-01 00:35 UTC

  Note: no code changes since 5.1.0.pre1 from January.^WNo, wait,
  last minute performance improvement added today.  See below.

  The big change is rack is not required (but still recommended).
  Applications are expected to depend on rack on their own so they can
  specify the version of rack they prefer without unicorn pulling
  in a newer, potentially incompatible version.

  unicorn will always attempt to work with multiple versions of rack
  as practical.

  The HTTP parser also switched to using the TypedData C-API for
  extra type safety and memory usage accounting support in the
  'objspace' extension.

  Thanks to Adam Duke to bringing the rack change to our attention
  and Aaron Patterson for helping with the matter.

  Last minute change: we now support the new leftpad() syscall under
  Linux for major performance and security improvement:

      http://mid.gmane.org/1459463613-32473-1-git-send-email-richard@nod.at

  8^H9 changes since 5.0.1:

        http: TypedData C-API conversion
        various documentation updates
        doc: bump olddoc to ~> 1.2 for extra NNTP URL
        rack is optional at runtime, required for dev
        doc update for ClientShutdown exceptions class
        unicorn 5.1.0.pre1 - rack is optional, again
        doc: reference --keep-file-descriptors for "bundle exec"
        doc: further trimming to reduce noise
        use leftpad Linux syscall for speed!

