Rtmp to http fallback

To test:
 - edit ```pages/SiteAmazonCdnMediaManifestPage.php``` and change the port to something out of range like ```123456789```
 - to see the "no HTML5 video message", edit ```www/javascript/site-jw-player-media-display.js``` and short-circuit the ```isHTML5VideoSupported()``` method with ```return false;```.