Patch for some browsers.

The event load or readystatechange don't fire to *tag LINK* (CSS) in:
- iOS < 6       (default mobile browser)
- Android < 4.4 (default mobile browser)
- Safari < 6    (desktop browser)

Then use a patch found in:
https://github.com/kof/xLazyLoader/blob/master/src/jquery.xLazyLoader.js#L163
but applied to browsers with the problem