PHP-941: Throw MongoConnectionException on stream failures

We need to be careful to restore it after each stream call, and most
importantly before mongo_manager_log(), otherwise those log entries
could throw exception
Add test for converting a stream warning into exception
Fix build with PHP 5.2 from 2006
Skip test on 5.2, tottally different looking exception
Update to use macros for PHP 5.2 compatability
Merge pull request #558 from bjori/PHP-941-throw-mongoprotocol-on-stream-failure

PHP-941: Throw MongoConnectionException on stream failures

* bjori/PHP-941-throw-mongoprotocol-on-stream-failure:
  Update to use macros for PHP 5.2 compatability
  Skip test on 5.2, tottally different looking exception
  Fix build with PHP 5.2 from 2006
  Add test for converting a stream warning into exception
  PHP-941: Throw MongoConnectionException on stream failures