Add return of  to all setters of View object. Allows chaining of methods...

Adds return $this; for all setter methods allowing chaining of calls. For example:
```
echo ipView('_footer.php')->setVariable('variable', 'value')->render(); 
```
As these methods was return void there is no really API change, so should be safe to merge.

And i suggest using same way for other object in similar use.