Merge pull request phonegap#900 from markus-olsson/avsession-leak

Fix for memory warnings due to AVCaptureSession leak

Author: devgeeks

iOS/BarcodeScanner/CDVBarcodeScanner.mm

@@ -300,7 +300,7 @@ - (void)barcodeScanCancelled {
 - (NSString*)setUpCaptureSession {
     NSError* error = nil;
 
-    AVCaptureSession* captureSession = [[AVCaptureSession alloc] init];
+    AVCaptureSession* captureSession = [[[AVCaptureSession alloc] init] autorelease];
     self.captureSession = captureSession;
 
     AVCaptureDevice* device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];