fixes leafo#144 and leafo#177

Author: robocoder

scss.inc.php

@@ -2991,7 +2991,7 @@ protected function parseChunk() {
 
 			// doesn't match built in directive, do generic one
 			if ($this->literal('@', false) && $this->keyword($dirName) &&
-				($this->openString('{', $dirValue) || true) &&
+				($this->variable($dirValue) || $this->openString('{', $dirValue) || true) &&
 				$this->literal('{'))
 			{
 				$directive = $this->pushSpecialBlock('directive');

tests/inputs/mixins.scss

@@ -156,3 +156,16 @@ div {
 #please-wait {
   @include logo(1em, $left: 4em, $bottom: 3em);
 }
+
+@mixin keyframes( $name )
+{
+    @-webkit-keyframes $name {
+        @content;
+    }
+}
+
+@include keyframes( change-color )
+{
+    0% { color: green; }
+    100% { color: red; }
+}

tests/outputs/mixins.css

@@ -81,3 +81,10 @@ div.mixin-content-with-arg {
   right: 0;
   bottom: 3em;
   left: 4em; }
+
+@-webkit-keyframes change-color {
+  0% {
+    color: green; }
+
+  100% {
+    color: red; } }