Most recent serializations in JSONs may have incorrectness

[pedropaulofb]

Some users reported problems when manipulating the models' serializations in JSON. There is already a not-released version of the JSON serialization that corrects this problem.

This issue is going to substitute the old form of reporting the necessity of a clan JSON generation (i.e., instead of opening individual issues for each model added to the catalog, we're going to keep only this issue open).

[pedropaulofb]

This issue aggregates the following related issues, which were closed for this reason:

#245
#238
#232