LPS-25955 Added video for Web content

Hi Sergio,

Here is the basic video for web content working. Anyway there are some things can be done for enhancing:

* Disable CKEditor video plugin if Xuggler is disabled.
* Not show files that hasn't a video preview in CKEditor file browser.
* Use Alloy UI video javascript component for creating video element in DOM, instead of using source "manually"
* Only write MP4 or OGG depending in Liferay portal properties (dl.file.entry.preview.video.containers).

Thanks Sergio!