Fixed CommonJS module pattern implementation

partially reverted d0dcd0cf to ensure BC with existing
CasperJS scripts.

@@ -4,10 +4,10 @@ CasperJS Changelog
 XXXX-XX-XX, v1.0.0 (currently latest master)
 --------------------------------------------
 
-### Important Changes
+### Important Changes & Caveats
 
 - **PhantomJS 1.6 is now the minimal requirement**
-- The `modules` directory has been renamed to `node_modules` for compatibility purpose with PhantomJS 1.7.
+- CasperJS continues to ship with its own implementation of CommonJS' module pattern, due to the way it has to work to offer its own executable. While the implementations are nearly the same, **100% compatibility is not guaranteed**.
 
 ### Bugfixes & enhancements
 

@@ -54,26 +54,20 @@ if (typeof Function.prototype.bind !== "function") {
 }
 
 /**
- * Only for PhantomJS < 1.7: Patching require() to allow loading of other
- * modules than PhantomJS' builtin ones.
+ * CasperJS ships with its own implementation of CommonJS' require() because
+ * PhantomJS' native one doesn't allow to specify supplementary, alternative
+ * lookup directories to fetch modules from.
  *
  */
-function patchRequire(require, requireDir) {
+function patchRequire(require, requireDirs) {
     "use strict";
+    require('webserver'); // force generation of phantomjs' require.cache for the webserver module
     var fs = require('fs');
-    var phantomBuiltins = ['fs', 'webpage', 'webserver', 'system'];
+    var phantomBuiltins = ['fs', 'webpage', 'system', 'webserver'];
     var phantomRequire = phantom.__orig__require = require;
     var requireCache = {};
-    return function _require(path) {
-        var i, dir, paths = [],
-            fileGuesses = [],
-            file,
-            module = {
-                exports: {}
-            };
-        if (phantomBuiltins.indexOf(path) !== -1) {
-            return phantomRequire(path);
-        }
+    function possiblePaths(path, requireDir) {
+        var dir, paths = [];
         if (path[0] === '.') {
             paths.push.apply(paths, [
                 fs.absolute(path),
@@ -84,6 +78,7 @@ function patchRequire(require, requireDir) {
         } else {
             dir = fs.absolute(requireDir);
             while (dir !== '' && dir.lastIndexOf(':') !== dir.length - 1) {
+                paths.push(fs.pathJoin(dir, 'modules', path));
                 // nodejs compatibility
                 paths.push(fs.pathJoin(dir, 'node_modules', path));
                 dir = fs.dirname(dir);
@@ -91,6 +86,21 @@ function patchRequire(require, requireDir) {
             paths.push(fs.pathJoin(requireDir, 'lib', path));
             paths.push(fs.pathJoin(requireDir, 'modules', path));
         }
+        return paths;
+    }
+    var patchedRequire = function _require(path) {
+        var i, paths = [],
+            fileGuesses = [],
+            file,
+            module = {
+                exports: {}
+            };
+        if (phantomBuiltins.indexOf(path) !== -1) {
+            return phantomRequire(path);
+        }
+        requireDirs.forEach(function(requireDir) {
+            paths = paths.concat(possiblePaths(path, requireDir));
+        });
         paths.forEach(function _forEach(testPath) {
             fileGuesses.push.apply(fileGuesses, [
                 testPath,
@@ -133,6 +143,8 @@ function patchRequire(require, requireDir) {
         requireCache[file] = module;
         return module.exports;
     };
+    patchedRequire.patched = true;
+    return patchedRequire;
 }
 
 function bootstrap(global) {
@@ -243,9 +255,7 @@ function bootstrap(global) {
         })(phantom.casperPath);
 
         // patch require
-        if (phantom.version.major === 1 && phantom.version.minor < 7) {
-            global.require = patchRequire(global.require, phantom.casperPath);
-        }
+        global.require = patchRequire(global.require, [phantom.casperPath, fs.workingDirectory]);
 
         // casper cli args
         phantom.casperArgs = global.require('cli').parse(phantom.args);

@@ -836,7 +836,7 @@ Casper.prototype.injectClientUtils = function injectClientUtils() {
     if (true === clientUtilsInjected) {
         return;
     }
-    var clientUtilsPath = require('fs').pathJoin(phantom.casperPath, 'node_modules', 'clientutils.js');
+    var clientUtilsPath = require('fs').pathJoin(phantom.casperPath, 'modules', 'clientutils.js');
     if (true === this.page.injectJs(clientUtilsPath)) {
         this.log("Successfully injected Casper client-side utilities", "debug");
     } else {