Merge: parser: add a basic sabblecc3 parser in Java

So one can more easily play and compare parsers.

Sometime, when I have issues with the parser, it helps to understand if it is nit-related, sablecc-related or grammar-relater.

Pull-Request: #1240
Reviewed-by: Alexandre Terrasa <alexandre@moz-code.org>
Reviewed-by: Alexis Laferrière <alexis.laf@xymus.net>