Feed 2.0

Now we can use RSS and Atom (WIP) through `Feed::instance`:

Examples:
```php
$feed = Feed::instance(); // Gleez_Rss object
$feed = Feed::instance('atom'); // Gleez_Atom object
```

Now Feed is abstract class for both classes.

<hr>

Also:
+ Moved `FILE_SECURITY` constant
+ Refactoring for `Gleez::getVersion` (old `Gleez::get_version`)
+ Amended Russian
+ Updated Feed Template Controller
+ Changed Gleez version

@sandeepone  Please see & check `Feed` & `Gleez_Rss` classes

`@todo` WIP. Need to implement `Gleez_Atom`