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.

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Also:
+ Moved `FILE_SECURITY` constant
+ Refactoring for `Gleez::getVersion` (old `Gleez::get_version`)
+ Amended Russian
+ Updated Feed Template Controller