I have seen you use `-i` instead of `--dump-header`+ print_headers() in JSON tests. However, this precludes of implementing the issue "facet" described in https://github.com/telefonicaid/fiware-orion/issues/101#issuecomment-30237813 (i.e. using the mjson.tool the same way XML tests use xmllint).

It makes sense to modify all the JSON tests included in this PR and complete the work in a short timeframe (1-2 days)? Or it is a too large/complex task and it is better to leave for the moment when we continue working on #101 ?