5.3.0

CHANGES:

• Port standard plugins to ppxlib registration and attributes
  #263
  (Simmo Saan)

• Optimize forwarding in eq and ord plugins
  #252
  (Simmo Saan)

• Delegate quoter to ppxlib
  #263
  (Simmo Saan)

• Introduce Ppx_deriving_runtime.Stdlib with OCaml >= 4.07.
  This module already exists in OCaml < 4.07 but was missing otherwise.
  #258
  (Kate Deplaix)