auto embed video modification

[cKleinhuis]

fyi:

 

the auto embed plugin that replaces videos with the embed html code has been adjusted by me in the following ways:

- provide https vimeo embedding
- 16:9 embed format now: 625x350 same height as before just wider
- "huge" embed feature added, by adding a "huge" to the host name, videos are going to be embedded double sized namely 1250x700
    the urls become then "youtubehuge.com" or "vimeohuge.com" respectively