Support for AMD usage of jwplayer (require js)

使用require js 模块化代码时，其中播放器用的是jwplayer7.x 然后载入jwplayer.js后总是报license无效（license已经加入），最后在jwplayer官网论坛里找到问题：

The reason seems to be that the flash player needs access to

window.jwplayer

.

window.jwplayer

is not set when using AMD (or CommonJS), therefore the flash player doesn't work.

While waiting for a fix, a workaround is to simply set

window.jwplayer

in the app's code:

define(['jwplayer'], function (jwplayer) {
window.jwplayer = jwplayer;

...
})