sendLoaderToResourcePath:usingBlock helper for sending object loader from RKObjectManager

gistfile1.m

- (RKObjectLoader *)sendLoaderToResourcePath:(NSString *)resourcePath usingBlock:(void (^)(RKObjectLoader *objectLoader))block {
    RKObjectLoader* loader = [self objectLoaderWithResourcePath:resourcePath delegate:nil];
    loader.serializationMIMEType = self.serializationMIMEType;
    
    // Yield to the block for setup
    block(loader);
    
    [loader send];
    return loader;
}