Fixed numerous errors

* FIX: Missing argument 2 for wpdb::prepare() in window.php - TinyMCE button now works properly	
* FIX: Missing argument 2 for wpdb::prepare() in ranking.php - PHPLeague Ranking widget now works properly	
* FIX: tinymce.js - TinyMCE shortcode button now properly inserts shortcode into content editor
* FIX: Single fixture ([phpleague type=fixture id=]) now shows fixture for new leagues (previously only displayed single fixture for first league created (ID = 1))
* FIX: In some cases date wasn't showing, fixed
* FIX: Msg "The fixture does not exist. Please resave fixtures." although fixture where saved