Providing a basic hint in the exception message about the server that caused
a connection exception could be useful especially with aggregated connections.
This is in response to issue #110.
Connection classes should just handle, convert and return simple Redis
types while parsing and transforming structured replies should be done
by consumers (see Predis\Client or Predis\Transaction\MultiExecContext).
This actually makes more sense considering that parsing a complex response
with the associated command parser may require different actions. As an
example, the result of EXEC is a multibulk that holds the actual responses,
so we really need to parse each one of its elements and we should also
make sure that iterable multibulks are consumed. We already did that
previously, but it was weird knowing that command parsers were applied
by the connection class.
This also moves some duplicated logic away from each connection class
implementation which is a nice bonus.
Daniele Alessandri