fixes #260 - Don't display test error messages when not testing

@@ -269,6 +269,7 @@ function bootstrap(global) {
             phantom.exit(0);
         } else if (phantom.casperArgs.get(0) === "test") {
             phantom.casperScript = fs.absolute(fs.pathJoin(phantom.casperPath, 'tests', 'run.js'));
+            phantom.casperTest = true;
             phantom.casperArgs.drop("test");
         } else if (phantom.casperArgs.get(0) === "selftest") {
             phantom.casperScript = fs.absolute(fs.pathJoin(phantom.casperPath, 'tests', 'run.js'));

@@ -610,9 +610,19 @@ Tester.prototype.comment = function comment(message) {
     this.casper.echo('# ' + message, 'COMMENT');
 };
 
+/**
+ * Configure casper callbacks for testing purpose.
+ *
+ */
 Tester.prototype.configure = function configure() {
     "use strict";
     var tester = this;
+
+    // Do not hook casper if we're not testing
+    if (!phantom.casperTest) {
+        return;
+    }
+
     // specific timeout callbacks
     this.casper.options.onStepTimeout = function test_onStepTimeout(timeout, step) {
         tester.fail(f("Step timeout occured at step %d (%dms)", step, timeout));