Add support for @font-face, which should not be considered a selector

This change stringifies `@font-face` at-rules, instead of treating them as a standard rule with `@font-face` being the selector.

Relates reworkcss/css-parse#75

lib/compress.js

@@ -144,6 +144,17 @@ Compiler.prototype.page = function(node){
     + this.emit('}');
 };
 
+/**
+ * Visit font-face node.
+ */
+
+Compiler.prototype['font-face'] = function(node){
+  return this.emit('@font-face', node.position, true)
+    + this.emit('{')
+    + this.mapVisit(node.declarations)
+    + this.emit('}');
+};
+
 /**
  * Visit rule node.
  */

lib/identity.js

@@ -174,6 +174,19 @@ Compiler.prototype.page = function(node){
     + this.emit('\n}');
 };
 
+/**
+ * Visit font-face node.
+ */
+
+Compiler.prototype['font-face'] = function(node){
+  return this.emit('@font-face ', node.position, true)
+    + this.emit('{\n')
+    + this.emit(this.indent(1))
+    + this.mapVisit(node.declarations, '\n')
+    + this.emit(this.indent(-1))
+    + this.emit('\n}');
+};
+
 /**
  * Visit rule node.
  */

test/cases/font-face.compressed.css

@@ -0,0 +1 @@
+@font-face{font-family:"Bitstream Vera Serif Bold";src:url("http://developer.mozilla.org/@api/deki/files/2934/=VeraSeBd.ttf");}body{font-family:"Bitstream Vera Serif Bold", serif;}

test/cases/font-face.css

@@ -0,0 +1,8 @@
+@font-face {
+  font-family: "Bitstream Vera Serif Bold";
+  src: url("http://developer.mozilla.org/@api/deki/files/2934/=VeraSeBd.ttf");
+}
+
+body {
+  font-family: "Bitstream Vera Serif Bold", serif;
+}