Revert r8795; instead, fix the tests by skipping them if running in a PHP environment < 5.3.

The https://core.trac.wordpress.org/changeset/29251 change in WordPress trunk/4.0's unit test suite surfaces a bug in PHP 5.2 environments which causes segfaults with `_destruct()` for static class variables. See https://bugs.php.net/bug.php?id=51822.

As the new tests are only failing in PHP 5.2.17 with WP trunk (at revision 29466 at time of writing), we've decided to fix by requiring the `date_query` unit tests run only in PHP 5.3+ environments.


git-svn-id: https://buddypress.svn.wordpress.org/trunk@8796 cdf35c40-ae34-48e0-9cc9-0c9da1808c22