issue-886: fixed memory leak with previousNavigationDelegate and previousTabBarDelegate

.gitignore

@@ -16,12 +16,7 @@ profile
 *.moved-aside
 *.playground
 *.framework
-Sources/Frameworks/Motion/.git*
-Sources/Frameworks/Motion/.gitignore
-Sources/Frameworks/Motion/.swift-version
-Sources/Frameworks/Motion/CONTRIBUTING.md
-Sources/Frameworks/Motion/Motion.podspec
-Sources/Frameworks/Motion/Motion.xcodeproj/
-Sources/Frameworks/Motion/Sources/Info.plist
-Sources/Frameworks/Motion/Sources/Motion.h
+DerivedData
+Index
+Build
 

Sources/Frameworks/Motion/Sources/Extensions/Motion+UIViewController.swift

@@ -47,13 +47,13 @@ fileprivate struct AssociatedInstance {
      A reference to the previous navigation controller delegate 
      before Motion was enabled.
      */
-    var previousNavigationDelegate: UINavigationControllerDelegate?
+    weak var previousNavigationDelegate: UINavigationControllerDelegate?
     
     /**
      A reference to the previous tab bar controller delegate 
      before Motion was enabled.
      */
-    var previousTabBarDelegate: UITabBarControllerDelegate?
+    weak var previousTabBarDelegate: UITabBarControllerDelegate?
 }
 
 extension UIViewController {