Multibulk response iterators will not be passed anymore to the response
parser method of the command that generated the response. Pipeline and
transaction abstractions still consume interators returned as response
items.
The reason for this change is to support the upcoming redis-cluster since
it has different behaviors compared to the client-side cluster implementation
provided by Predis. For example redis-cluster will not support key tags or
certain operations currently available with our client-side implementation.