Use DS for path separator.

Minor correction for output display in shells on WIN

Before:
```
Current Paths:

* app: src
* root: E:\PHP\wamp\www\work\app30\app
* core: E:\PHP\wamp\www\work\app30\app/vendor/cakephp/cakephp
```

After:
```
Current Paths:

* app: src
* root: E:\PHP\wamp\www\work\app30\app
* core: E:\PHP\wamp\www\work\app30\app\vendor\cakephp\cakephp
```