Issue #151 pointed to a flaw in how command instances were converted
to strings: we were simply truncating their arguments when exceeding
a certain size as this was mostly intended for logging or debugging,
but this approach breaks strings containing multibyte characters so
we decided to drop this feature altogether for the sake of simplicity.
It is still possible to replicate the same (and eventually improved)
behavior externally by fetching ID and arguments of a command out of
a command instance using the public methods made available by the
Predis\Command\CommandInterface.