New feature: [vid] tag

Guerrilla

@McC over on our Discord asked if it would be possible to embed video files inline on the forums. So, after fiddling with the code a little, I'm proud to present to you the vid tag. (video was taken).

Works the same way as an img tag. Basically just add

[vid]URL[/vid]

in your posts to embed videos. If it's a HTML5 supported format, it should play fine. I would like to ask you to host the video files yourself, since I'm not made out of disk space, but other than that, go nuts.