Setting SapphireTest::is_running_test() in PHPUnit bootstrap

Otherwise conditional logic will only succeed
when run through "sake dev/tests", not when
run through phpunit directly (which is the recommended way now)

dev/SapphireTest.php

@@ -131,6 +131,9 @@ class SapphireTest extends PHPUnit_Framework_TestCase {
 		return self::$is_running_test;
 	}
 
+	public static function set_is_running_test($bool) {
+		self::$is_running_test = $bool;	
+	}
 
 	/**
 	 * Set the manifest to be used to look up test classes by helper functions

tests/bootstrap.php

@@ -61,6 +61,8 @@ $controller = new FakeController();
 // Get test manifest
 TestRunner::use_test_manifest();
 
+SapphireTest::set_is_running_test(true);
+
 // Remove the error handler so that PHPUnit can add its own
 restore_error_handler();