Common gift type feature

[smoneuse]

Some gifts are expansive.
Users can't ask a unique user to reverse a gift with such high cost.

Here comes the "Common gift" feature.
When creating/udating a gift : the creator can specify that this gift is a "participation gift"
On a friend's list, all participation typed gifts should have a "Participate" button displayed instead of "book this gift"
-> as usual, it is asked when the friend wants to deliver its participation.
-> A participation gift remains visible to other users to participate too.

The creator of a participation gift can indicate when the gift is considered as fully participated : then the gift status is updated to "GIVEN" and no more available for the user's friends.

On gifts history, a participation gift is displayed with the last participation delivery date and all users who have participated.