Trailing whitespace cleanup from files in the Code directory.

Used the following command from within the Code dir:
git ls-files *.m *.h *.json | xargs /usr/bin/sed -i '' -E 's/[[:space:]]*$//'

Code/ObjectMapping/RKManagedObjectRequestOperation.m

@@ -148,7 +148,7 @@
         RKLogDebug(@"Skipping deletion of orphaned objects: deletesOrphanedObjects=NO");
         return YES;
     }
-    
+
     if (! [[self.requestOperation.request.HTTPMethod uppercaseString] isEqualToString:@"GET"]) {
         RKLogDebug(@"Skipping cleanup of objects via managed object cache: only used for GET requests.");
         return YES;