Feature/8830

Previously (mis)using Flash version of flowplayer so have switched over to correct method (see http://flowplayer.org/docs/setup.html).

Have dropped in minimal skin (flowplayer.less) and library (flowplayer.js) which are pretty lean. At the moment the Flash version of the player is loaded from vendor site, but we can embed this if needed.

We might not need to use transcript any more as the player supports subtitles - please advise.

Note also that audio tag is not supported. Have looked around at different players and used comparisons (http://praegnanz.de/html5video/) to determine alternatives. mediaelement.js next most promising, but has much larger code footprint (70kB) and MIT license.