Introduce switchPath to repetition.

Currently fails on "External object 'owner' not found in user objects."
Unsucceseful attempt to fix the following error:

Uncaught Error: External object 'owner' not found in user objects. reviver.js:220
Object.defineProperties.reviveExternalObject.value reviver.js:220
Object.defineProperties.reviveRootObject.value reviver.js:75
Object.defineProperties.getObject.value context.js:40
Object.defineProperties.getObjects.value context.js:66
Montage.specialize.call.instantiate.value montage-interpreter.js:32
Montage.specialize.call.deserialize.value montage-deserializer.js:57
Montage.specialize._instantiateObjects.value template.js:386
Montage.specialize.instantiateWithInstances.value template.js:271
Montage.specialize.instantiate.value template.js:241
(anonymous function) repetition.js:1005
_fulfilled q.js:798
self.promiseDispatch.done q.js:827
Promise.promise.promiseDispatch q.js:760
(anonymous function) q.js:574
flush q.js:108
Assign the original instance to fix "Uncaught Error: External object 'owner' not found in user objects." error.