v3.1.0

v3.1.0 (minor release)

This minor release adds support for OCaml 4.11.

• Compatibility fixes for OCaml-4.11
  #962
  (Jerome Vouillon)

• BatEnum: added combination
  #518
  (Chimrod, review by hcarty)

• fix benchmarks
  #956
  (Cedric Cellier)

• BatFile: added count_lines
  #953
  (Francois Berenger, review by Cedric Cellier)

• BatArray: use unsafe_get and unsafe_set more often
  #947
  (Francois Berenger, review by Cedric Cellier)

• fix some tests for ocaml-4.10.0
  #944
  (kit-ty-kate)

• BatResult: BatPervasives.result is now equal to Stdlib.result
  instead of sharing constructors without being the same type
  #939, #957
  (Clément Busschaert, Cedric Cellier).