Controller_Userguide: update typo, fix vars

Base description for some methods and properties.
`Controller_Userguide::$api` not used. 
`Controller_Userguide::after()`: route 'media' already setted in `Controller_Userguide::before()`, `$this->template->translations` not used.
Well first of all, PSR2 doesn't apply - we follow the (older) [Kohana conventions](http://kohanaframework.org/3.3/guide/kohana/conventions).

Second, just because a coding standard allows a longer line doesn't mean it's a good idea and definitely doesn't justify removing line breaks just to fill up the allowed width.

Coding standards generally allow long lines to cater for things like strings, long method or class names, long call chains or whatever. It usually helps readability to break separate logical statements onto separate lines wherever possible.

Even if we were using PSR2 you missed the subsequent quote:

> There MUST NOT be more than one statement per line.

Each of those logical expressions inside that if is, as far as I'm concerned, a separate statement.