Create a decorator to represent a many to one relationship.

[lsoaresesilva]

Acceptance test

1. A decorator must be used @manytoone({document:Class.prototype})
2. A property _manyToOne must be dynamically created to represent an array of documents
3. In the get method, they must verify if there is a _manyToOne property. If it exists, a GET on the Document must be fetch based on the id.
4. In the add method, they must verify if there is a _manyToOne property. If it exists, must call add on the document to save or update it.
5. Unit tests

[lsoaresesilva]

Points 1, 2, 3 are implemented.

[lsoaresesilva]

Point 4 implemented.