Remove use of __weak, which XCode 7.3 disallows with manual ref counting

sources/GTMCarbonEvent.h

@@ -230,16 +230,7 @@ GTM_EXTERN NSUInteger GTMCarbonToCocoaKeyModifiers(UInt32 inCarbonModifiers);
 //
 // Subclasses are expected to override the eventTarget and
 // handleEvent:handler: methods to customize them.
-@interface GTMCarbonEventHandler : NSObject {
- @private
-  // handler we are wrapping
-  // lazily created in the eventHandler method
-  EventHandlerRef eventHandler_;
-  __weak id delegate_;  // Our delegate
-  // Does our delegate respond to the gtm_eventHandler:receivedEvent:handler:
-  // selector? Cached for performance reasons.
-  BOOL delegateRespondsToHandleEvent_;
-}
+@interface GTMCarbonEventHandler : NSObject
 // Registers the event handler to listen for |events|.
 //

sources/GTMCarbonEvent.m

@@ -351,7 +351,15 @@ NSUInteger GTMCarbonToCocoaKeyModifiers(UInt32 inCarbonModifiers) {
 const OSType kGTMCarbonFrameworkSignature = 'GTM ';
-@implementation GTMCarbonEventHandler
+@implementation GTMCarbonEventHandler {
+  // handler we are wrapping
+  // lazily created in the eventHandler method
+  EventHandlerRef eventHandler_;
+  id delegate_;  // Our delegate (weak reference)
+  // Does our delegate respond to the gtm_eventHandler:receivedEvent:handler:
+  // selector? Cached for performance reasons.
+  BOOL delegateRespondsToHandleEvent_;
+}
 // Does our delegate respond to eventHandler:receivedEvent:handler:
 //

sources/ThreeFingerTapGestureRecognizer.m

@@ -14,7 +14,7 @@
     int numTouches_;
     NSTimeInterval firstTouchTime_;  // Time since ref date of transition from 0 to >0 touches
     NSTimeInterval threeTouchTime_;  // Time since ref date of transition from <3 to 3 touches
-    __weak NSView *target_;
+    NSView *target_;  // weak reference
     SEL selector_;
     BOOL fired_;  // True if we just faked a three-finger click and future mouse clicks should be ignored.
 }

sources/iTermToolWrapper.h

@@ -58,7 +58,7 @@
 @interface iTermToolWrapper : NSView
 @property(nonatomic, copy) NSString *name;
-@property(nonatomic, readonly) __weak NSView *container;
+@property(nonatomic, readonly) NSView *container;
 @property(nonatomic, assign) id<ToolWrapperDelegate> delegate;
 @property(nonatomic, readonly) id<ToolbeltTool> tool;
 @property(nonatomic, readonly) CGFloat minimumHeight;

sources/iTermToolWrapper.m

@@ -32,6 +32,10 @@ static const CGFloat kCloseButtonLeftMargin = 5;
 @end
+@interface iTermToolWrapper()
+@property(nonatomic, readwrite, assign) NSView *container;
+@end
+
 @implementation iTermToolWrapper {
     NSTextField *_title;
     NSButton *_closeButton;