Issue #1704 New album edition page

* Front end development according to the mockup
* Save changes in ajax
* Implement the delete album behaviour with Jconfirm in ajax
* Adding a new Css component : infos (factorized in the tag page)
* Add a new general admin template variable : ADMIN_PAGE_OBJECT_ID (adding the id of an object on the page)
* Modify the pwg.categories.setInfo api method to fit the need of the album edition pages
* Slightly change the method time_since, add a parameter to display only the greates time unit
* Popin to change parent album, and changed it as a re-usable component
* Dropdown to replace the checkbox for comments

include/functions_html.inc.php

@@ -136,7 +136,7 @@ SELECT id, name, permalink
     }
     else
     {
-      $output.= $conf['level_separator'];
+      $output.= '<span>'.$conf['level_separator'].'</span>';
     }
 
     if ( !isset($url) or $single_link )