made the test suite more compatible with old versions of PHPUnit

phpunit.xml

@@ -6,7 +6,7 @@
          convertErrorsToExceptions="true"
          convertNoticesToExceptions="true"
          convertWarningsToExceptions="true"
-         processIsolation="false"
+         processIsolation="true"
          stopOnFailure="false"
          syntaxCheck="false"
 >

test/Twig/Tests/Extension/SandboxTest.php

@@ -15,7 +15,7 @@ class Twig_Tests_Extension_SandboxTest extends PHPUnit_Framework_TestCase
 {
   static protected $params, $templates;
 
-  static public function setUpBeforeClass()
+  public function setUp()
   {
     self::$params = array(
       'name' => 'Fabien',

test/Twig/Tests/TokenStreamTest.php

@@ -15,7 +15,7 @@ class Twig_Tests_TokenStreamTest extends PHPUnit_Framework_TestCase
 {
   static protected $tokens;
 
-  static public function setupBeforeClass()
+  public function setUp()
   {
     self::$tokens = array(
       new Twig_Token(Twig_Token::TEXT_TYPE, 1, 0),

test/Twig/Tests/integrationTest.php

@@ -15,7 +15,7 @@ class Twig_Tests_IntegrationTest extends PHPUnit_Framework_TestCase
 {
   static protected $fixturesDir;
 
-  static public function setUpBeforeClass()
+  public function setUp()
   {
     self::$fixturesDir = realpath(dirname(__FILE__).'/../../fixtures/');
   }