Directory independent extensions

Comparing #3 with #5

Content

## How to implement directory independent extensions Many people want to use downloaded extensions in their own way. As for me the most of the extensions are require me to correct [`Yii::import()`](http://www.yiiframework.com/doc/api/1.1/YiiBase/#import-detail) instructions inside their source code. All these extensions are directory dependent. To avoid athe situation described above, I suggest to implement pseudo-anonymous aliases:

```php
[...]
// create alias
Yii::setPathOfAlias($alias,$dir);
// import
another classes
Yii::import($alias.'.anotherClass');
Yii::import($alias.'.andAnoTherClass');
[...]
```

Using this technique you can create
*really* directory-independent extensions.