Add macro support

tests/cases/Aspect/MacrosTest.php

@@ -0,0 +1,18 @@
+<?php
+namespace Aspect;
+
+class MacrosTest extends TestCase {
+
+    public function testMacros() {
+        $tpl = $this->aspect->compileCode('
+        {macro plus(x, y)}
+            x + y = {$x + $y}
+        {/macro}
+
+        Math: {macro.plus x=2 y=3}
+        ');
+
+        $this->assertStringStartsWith('x + y = ', trim($tpl->macros["plus"]["body"]));
+        $this->assertSame('Math: x + y = 5', Modifier::strip($tpl->fetch(array()), true));
+    }
+}