added utility for ListMonitor to return the index/indexPath of a specified object

CoreStore/Observing/ListMonitor.swift

@@ -273,6 +273,28 @@ public final class ListMonitor<T: NSManagedObject> {
         return sections[section]
     }
     
+    /**
+    Returns the index of the `NSManagedObject` if it exists in the `ListMonitor`'s fetched objects, or `nil` if not found.
+    
+    - parameter object: the `NSManagedObject` to search the index of
+    - returns: the index of the `NSManagedObject` if it exists in the `ListMonitor`'s fetched objects, or `nil` if not found.
+    */
+    public func indexOf(object: T) -> Int? {
+        
+        return (self.fetchedResultsController.fetchedObjects as? [T] ?? []).indexOf(object)
+    }
+    
+    /**
+    Returns the `NSIndexPath` of the `NSManagedObject` if it exists in the `ListMonitor`'s fetched objects, or `nil` if not found.
+    
+    - parameter object: the `NSManagedObject` to search the index of
+    - returns: the `NSIndexPath` of the `NSManagedObject` if it exists in the `ListMonitor`'s fetched objects, or `nil` if not found.
+    */
+    public func indexPathOf(object: T) -> NSIndexPath? {
+        
+        return self.fetchedResultsController.indexPathForObject(object)
+    }
+    
     /**
     Registers a `ListObserver` to be notified when changes to the receiver's list occur.