Fixed rejection of case-insensitive configuration values when there is a set of allowed values. This manifested in %Core.Encoding.

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@367 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/Encoder.php

@@ -23,6 +23,11 @@ if ( !function_exists('iconv') ) {
             'iso-8859-1'
         )
     );
+    HTMLPurifier_ConfigDef::defineValueAliases(
+        'Core', 'Encoding', array(
+            'iso8859-1' => 'iso-8859-1'
+        )
+    );
 }
 
 /**