In `general-template.php` - remove dead code:

* In `get_calendar()`, `$cache` is set twice. The first is useless. 
* In `wp_default_editor()`, `$user` is (accidentally) assigned in a condition. Since it is never used, this is unnecessary.
* In `language_attributes()`, `$output` is set twice before it is ever used. The first is unnecessary. 
* In `paginate_links()`, `$n` is set twice before it is ever used. The first is unnecessary.

See #27882.



git-svn-id: https://develop.svn.wordpress.org/trunk@28274 602fd350-edb4-49c9-b593-d223f7449a82