Added tearDown() method to clear ContextHolder.

core/src/test/java/org/acegisecurity/taglibs/authz/AuthorizeTagAttributeTests.java

@@ -68,4 +68,8 @@ public class AuthorizeTagAttributeTests extends TestCase {
 
         ContextHolder.setContext(context);
     }
+    
+    protected void tearDown() throws Exception {
+		ContextHolder.setContext(null);
+	}
 }

core/src/test/java/org/acegisecurity/taglibs/authz/AuthorizeTagTests.java

@@ -109,4 +109,8 @@ public class AuthorizeTagTests extends TestCase {
 
         ContextHolder.setContext(context);
     }
+
+    protected void tearDown() throws Exception {
+		ContextHolder.setContext(null);
+	}
 }