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.


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git-svn-id: http://core.svn.wordpress.org/trunk@28102 1a063a9b-81f0-0310-95a4-ce76da25c4cd