updated usage and handled when error.code is not present

lib/index.js

@@ -6,7 +6,7 @@ var http = require('http');
 var fs = require('fs');
 var async = require('async');
 var argv = require('optimist')
-    .usage('Usage: $0 [config] [config]...')
+    .usage('Usage: $0 config [config...]')
     .options('c', {
 	    alias: 'concurrency',
 	    default: 1,
@@ -227,7 +227,7 @@ queue.drain = function(){
 	    }
 	    console.log('Errors For: ' + url);
 	    console.log('\tErrors: ' + errors[url].length);
-	    var code_errors = errors[url].map( function(a){ return a.error.code; });
+	    var code_errors = errors[url].map( function(a){ return (a.error.code)?a.error.code:a.error; });
 	    var code_set = new gauss.Vector(code_errors);
 	    var code_dist = code_set.distribution();
 	    console.log('\tError Code Distribution:');