Merge pull request #650 from sorawee/master

Fix typo

lib/compile.js

@@ -275,7 +275,7 @@
             var name = unique(ruleName + "$macrocall");
             var macro = result.macros[token.macrocall];
             if (!macro) {
-                throw new Error("Unkown macro: "+token.macrocall);
+                throw new Error("Unknown macro: "+token.macrocall);
             }
             if (macro.args.length !== token.args.length) {
                 throw new Error("Argument count mismatch.");