Modification made in json files :
-header/footer uncompressed size (instead of compressed size)
-md5 of header (used in johnny's ird filename)
-renamed HEADER_LEN / FOOTER_LEN by HEADER_SIZE / FOOTER_SIZE

remove ext ".ird" + fix json
Add region/file type (encrypted/plain)
Extract data to json
check header size
fix endianness
improved help message