lib: retire the old 'json' module based on libjson0

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib: rename simple_json_reader as json::static

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib: intro the nicer to use json::dynamic

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/json: privatly import lexer and parser

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/json: improve doc of the static module
lib/json: intro the main module json.nit

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>