* Fixed a bug with shows that start at midnight not displaying in the on-air sidebar widget.
* Switched DJ/Show avatars in the widgets to use the featured image of the show instead of gravatar.
* Updated show template to get rid of a PHP warning that appeared if the show had no schedules. 
* Fixed some other areas of the code that were generating PHP notices in WordPress 3.6
* Added CSS classes to master program schedule output so CSS rules can be applied to specific shows
* Added new attribute to the list-shows shortcode to allow only specified genres to be displayed

git-svn-id: https://plugins.svn.wordpress.org/radio-station/trunk@775371 b8457f37-d9ea-0310-8a92-e5e31aec5664