The Piqi Project

Major changes include support for JSON encoding and providing compatibility
with OCaml 3.12.0.

Piqi tools:

  - "piqi convert" command now supports two new encodings: "json" (plain JSON)
    and "piq-json" (JSON with Piq type annotation for top-level objects).
  - A new command: "piqi json-pp" for pretty-printing JSON files.

Piqi language:

  - Added support for "json-name" property for type definitions, fields and
    options. When specified, it will be used as a name for correspondent JSON
    field names instead of "name".
  - Renamed "ignore-field" top-level directive to "custom-field".

Other changes:

  - Provided compatibility with the latest OCaml release (3.12.0). Improved
    support for older OCaml versions >= 3.10.