Implement webm thumbnail replacement.

Conflicts:
	LICENSE
	builds/4chan-X-beta.user.js
	builds/4chan-X.user.js
	src/General/css/style.css
	src/Images/AutoGIF.coffee
	src/Images/Gallery.coffee
	src/Images/ImageLoader.coffee
Clear event listener

Conflicts:
	builds/4chan-X-beta.user.js
	builds/4chan-X.user.js
Pause off screen and better clone handling for GIF/WebM etc. replacement
fix bug in WebM resetting
fix bug in WebM resetting
Release 4chan X v1.9.1.8.
Merge branch '1.9.1.x'
Allow WebM replacement in quote preview thumbnails.
don't need to save the old thumb anymore
Release 4chan X v1.9.2.0.
queue ImageLoader downloads
fix error
move to next item in queue if taking too long
Release 4chan X v1.9.2.1.
fix number of pages in search
Release 4chan X v1.9.1.9.
Merge branch '1.9.1.x'

Conflicts:
	CHANGELOG.md
	LICENSE
	builds/4chan-X-beta.crx
	builds/4chan-X-beta.meta.js
	builds/4chan-X-beta.user.js
	builds/4chan-X-noupdate.crx
	builds/4chan-X-noupdate.user.js
	builds/4chan-X.crx
	builds/4chan-X.meta.js
	builds/4chan-X.user.js
	builds/4chan-X.zip
	builds/updates-beta.xml
	builds/updates.xml
	package.json
no more common thread
Release 4chan X v1.9.2.2.
forgot to remove this in d533f0 (Allow WebM replacement in quote preview thumbnails.)