added warning for when trying to use casper in a node env

@@ -28,9 +28,14 @@
  *
  */
 
-/*global console, phantom, require:true*/
+/*global process, console, phantom, require:true*/
 /*jshint maxstatements:30, maxcomplexity:10*/
 
+// node check
+if (process && process.title === "node") {
+    console.error('CasperJS cannot be executed within a nodejs environment');
+}
+
 // phantom check
 if (!phantom) {
     console.error('CasperJS needs to be executed in a PhantomJS environment http://phantomjs.org/');