* Add new IEs
* MegaTVComBaseIE: Base IE class
* MegaTVComIE: Extract from TV VOD pages and news articles, i.e. all
sorts of pages showing videos on megatv.com
* MegaTVComEmbedIE: Extract iframe-embeddable megatv.com videos
* When video_id is not matched in the URL, namely for news articles,
extract it (article_id) from a particular element on the web page
* Derive metadata and sources directly from the web page, from data
attributes of the player placeholder element and other commonly used
elements
* Let MegaTVComEmbedIE defer to MegaTVComIE for extraction, as the
metadata on the embeddable page are some times slightly different, for
the same video
