Add example code for AwsException containing modeled exception data

Merge pull request #736 from howardlopez/aws_exception_data

Author: SCalwas

php/example_code/s3/ErrorHandling.php

@@ -54,6 +54,10 @@
     echo $e->getAwsRequestId() . "\n";
     echo $e->getAwsErrorType() . "\n";
     echo $e->getAwsErrorCode() . "\n";
+
+    // This dumps any modeled response data, if supported by the service
+    // Specific members can be accessed directly (e.g. $e['MemberName'])
+    var_dump($e->toArray());
 }
 
 // snippet-end:[s3.php.error_handling.client]