Description:
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Stomp sends all of the message properties as strings, when the 
actual data type is other.

Reproduce code:
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// PRODUCER
// .. set up stomp connection
$stomp->send($queue, 1, array('delay'=>90, 'openAfter'=> (int)(time() + 90)));

// CONSUMER
// .. set up stomp connection
$stomp->subscribe($queue ,array('selector' => 'openAfter > 1'));

Expected result:
----------------
We should receive the message sent by the producer

Actual result:
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No message is received. After further inspection, the most 
likely cause is that the 'openAfter' parameter is sent as a 
string rather than a int. ActiveMQ selector do not evaluate 
string into numeric values when using selectors, so we cannot 
use selectors/properties while using this Stomp library.