Fixed tests that fail with non-default `serialize_precision` configurations.

See:

 * https://bugs.php.net/bug.php?id=64760
 * 4dc4302
added a test to cover distinction between boolean return value of unserialize function and deserializing serialized boolean
Fix WS in serialization_error_002.phpt
Merge branch 'PHP-5.4' into PHP-5.5

* PHP-5.4:
  added a test to cover distinction between boolean return value of unserialize function and deserializing serialized boolean