Description:
------------
If an error occurs while attempting to perform a Memcached::get(), the result code will be set to RES_NOTFOUND.  However, that result is actually masking the more important error (such as connection failure, timed out, server is marked dead, etc...)

Replacing the Memcached::get() call with a Memcached::set() call results in the *correct* result code being reported.

Test script:
---------------
<?php

$mc = new Memcached();
$mc->addServer('10.2.3.4', 5555); // Server should not exist

$mc->setOption( Memcached::OPT_RETRY_TIMEOUT, 1 );

while (true)
{
  // Note how it changes if you remove either the get() call or the set() call.
  // Having only get(), results in "NOT FOUND" printed repeatedly.

  $result = $mc->get('foo');
  echo var_export( $result, true ), "; ", $mc->getResultCode( ), ': ', $mc->getResultMessage( ), "\n";

  $result = $mc->set('foo', 1, 0);
  echo var_export( $result, true ), "; ", $mc->getResultCode( ), ': ', $mc->getResultMessage( ), "\n";

  usleep(250000);
}

Expected result:
----------------
false; 3: CONNECTION FAILURE
false; 35: SERVER IS MARKED DEAD
false; 35: SERVER IS MARKED DEAD
false; 35: SERVER IS MARKED DEAD
false; 3: CONNECTION FAILURE
false; 35: SERVER IS MARKED DEAD
false; 35: SERVER IS MARKED DEAD
false; 35: SERVER IS MARKED DEAD
false; 3: CONNECTION FAILURE
...

Actual result:
--------------
false; 16: NOT FOUND
false; 35: SERVER IS MARKED DEAD
false; 16: NOT FOUND
false; 35: SERVER IS MARKED DEAD
false; 16: NOT FOUND
false; 35: SERVER IS MARKED DEAD
false; 16: NOT FOUND
false; 35: SERVER IS MARKED DEAD
...