Update usage to match latest changes

Author: lukeapage

lib/usage.js

@@ -4,15 +4,16 @@ module.exports = {
         console.log("Clean CSS Plugin");
         console.log("specify plugin with --clean-css");
         console.log("To pass an option to clean css, we use similar CLI arguments as from https://github.com/GoalSmashers/clean-css");
-        console.log("The exception is advanced - we turn it off by default so use advanced to turn it back on again.");
-        console.log("--clean-css=\"-s1 --advanced\"");
+        console.log("The exception is advanced and rebase - we turn these off by default so use advanced/rebase to turn it back on again.");
+        console.log("--clean-css=\"-s1 --advanced --rebase\"");
         console.log("The options do not require dashes, so this is also equivalent");
-        console.log("--clean-css=\"s1 advanced\"");
+        console.log("--clean-css=\"s1 advanced rebase\"");
         this.printOptions();
         console.log("");
     },
     printOptions: function() {
-        console.log("we support only arguments that make sense for less, 'keep-line-breaks', 'b'");
-        console.log("'s0', 's1', 'advanced', 'compatibility', 'rounding-precision'");
+        console.log("we support the following arguments... 'keep-line-breaks', 'b'");
+        console.log("'s0', 's1', 'advanced', 'rebase', 'keepSpecialComments', compatibility', 'rounding-precision'");
+        console.log("'skip-aggressive-merging', 'skip-shorthand-compacting'")
     }
 };