lib/simple_json_reader: unprotect special char in strings

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
phase/serialization: fix test_serialization_redef to suport basic deserialization

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
phase/serialization: detect unsupported case until it is supported

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