• Fix S.of_head for the HTTP client (regression introduced in 0.9.0)
• Fix regression in displaying the store's graph over HTTP introduced by
  0.9.0.
• Fix regression in watch handling introduced in 0.9.0.
• Fix regressions in Views introduced in 0.9.0. (thx @buzzheavyyear for
  the report)
• Always add a commit when calling a update function (Irmin.update
Irmin.remove, Irmin.remove_rec) even if the contents' store have
  not changed.
• The [head] argument of [Git_unix.config] now has a proper type.
• Expose synchronisation functions for basic Irmin stores.
• The user-provided merge function now takes optional values. The
  function is now called much more often during recursive merges
  (even if one of the 3 buckets of the 3-way merge function is not
  filled -- in that case, it uses None).
• Also expose the type of the keys in the type basic Irmin stores. Use
  ('key, 'value) Irmint.t instead of 'value Irmin.t.
• The user-defined merge functions now take the current filename being
  merged as an additional argument.
• The user-defined Contents should expose a Path sub-module. Keys of
  the resulting Irmin store will be of type Path.t.
• Fix irmin init --help. (#103)