A package enabling the creation of models who's data lives in one collection and is linked to many other collections.
This package is based on socialize:linkable. It's modified to make the linked object optional and adds an optional grandparent linked object as well.
LinkableModel - Extends BaseModel
LinkableModel.registerLinkableType(type, collection, options) - Register a child model as a linkable type
LinkableModel.getCollectionForRegisteredType(type) - Get the collection reference on a registered Linkable type
LinkableModel.prototype.linkedObject - Retrieve the object that is being linked to.
LinkableModel.prototype.parentLinkedObject - Retrieve the parent object that is being linked to.