Jwplayer 6.6 upgrade

I've installed the latest JW Player version, 6.6. We're currently running 6.4. You can see the JW Player changelog here: http://www.longtailvideo.com/support/jw-player/28835/release-notes/

New things worth noting:
 - "Fix: Smooth scaling of poster and playlist thumbnails in Flash mode." - I've changed our code for selecting the best image to always show a larger image than the player now that this is supported.
 - "Mobile players now use customizable skins instead of the device default controls" I may look into this for our HD icon

Things I've tested so far:

Platforms:
 - Flash and HTML5
 - Desktop and Mobile (iOS)

Processes:
 - recording end-point on lecture videos
 - firing the end-of-video event/overlay

Notes:
 - there appears to be a new feature that attempts to load a ```crossdomain.xml``` file from our cloudfront domain. I'm not sure whether that always gets fired, or whether it's just something to do with our stage environment. It can cause an extra HTTP request per video and currently returns a 403 error. I don't think we're using any of the settings that would normally need crossdomain.xml http://www.longtailvideo.com/support/jw-player/28844/crossdomain-file-loading