While YAJL mostly works fine, it did not see any active development in
the last 3 years. OTOH, Jansson is another JSON C implementation, with
a very liberal license, and a much nicer API.
Hence, switch all of libguestfs from YAJL to Jansson:
- configure checks, and buildsystem in general
- packages pulled in the appliance
- actual implementations
- contrib scripts
- documentation
This also makes use of the better APIs available (e.g. json_object_get,
json_array_foreach, and json_object_foreach). This does not change the
API of our OCaml Yajl module.