RealmSwift support

[markst]

It would be great if there were support for Realm's swift objects.
https://realm.io/docs/swift/latest/

[markst]

It seems that not a huge amount of work is required to support RealmSwift.

Since realm swift Object subclasses from RLMObjectBase rather than RLMObject.
The two categoriesRLMObject+JSONAPIParser & RLMObject+JSONAPIResource can both be categories on RLMObjectBase rather.

Since RealmSwift Objects have no createOrUpdateInRealm... I've been able to create a swift function on my model such as:

open class func createOrUpdate(inRealm: RLMRealm!, withValue: [AnyHashable : Any]!) -> User! {
    let realm = try! Realm()
    let user: User = realm.create(User.self, value: withValue, update: true)
    return user
}

Which will succeed in creating a valid Realm object upon JSONAPIParserUtilities constructObjectWithJSON:inRealm