Swift: Update Docs/Example Repos with use of dynamic keyword

[natevecc]

Was running into an issue where objects weren't updating when saving to the server. I managed to figure out that Swift doesn't support KVO out of the box: docs(see section Key-Value Observing).

Long story short when using Swift with the cloudmine-ios library make sure to add dynamic in objects that extend CMObject:

class MyClass: CMObject {
  // the right way. changes to this property will be picked up by KVO, the object will be marked 
  // dirty and saved when calling #save() or #saveWithUser()
  dynamic var myProperty: String?

  // the wrong way. changes will not be picked up by KVO and the object will never be marked 
  // as dirty and saved correctly
  var anotherProperty: String?
}

[ethanmick]

@pbenmoser4 @jraymondcm

[wjoshraymond]

@ethanmick thanks. We'll add a note to the documentation.

Do we know if extending CMObject is the only circumstance under which this would be necessary for our SDK?

[natevecc]

Also found another work around that works well with enums which don't support the dynamic keyword.

enum State: String {
  case Phase1
  case Phase2
}

class MyClass: CMObject {
  var myProperty: State {
    didSet: {
      self.dirty = true
    }
  }
}

[ethanmick]

@jraymondcm Yes, since CMObjects are the only class that uses the KVO to set themselves to dirty.

@natevecc Thanks for that example too. We should mention the CMObject dirty setting in our docs. I'll talk to @jraymondcm