[2.1.4] Add information about PHP 5.0.5 or earlier.

- Fix segfault in 5.0.x with IDAccumulator test.

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/branches/php4@1726 48356398-32a2-884e-a903-53898d9a118a

tests/HTMLPurifier/IDAccumulatorTest.php

@@ -32,7 +32,10 @@ class HTMLPurifier_IDAccumulatorTest extends HTMLPurifier_Harness
     
     function testBuild() {
         $this->config->set('Attr', 'IDBlacklist', array('foo'));
-        $accumulator = HTMLPurifier_IDAccumulator::build($this->config, $this->context);
+        // For some reason, doing the static call here results in a segfault
+        // for early versions of PHP 5.0.x
+        $acc = new HTMLPurifier_IDAccumulator();
+        $accumulator = $acc->build($this->config, $this->context);
         $this->assertTrue( isset($accumulator->ids['foo']) );
     }