Fix quoting inside inlined backlinks. Fix #900

Well that's interesting: selectors with Element.querySelector|All
will search for corresponding elements inside the whole document,
and will only return elements that are inside your given root element.

Conflicts:

	4chan_x.user.js
	script.coffee
$.hidden

Conflicts:

	4chan_x.user.js
	script.coffee
beep

Conflicts:

	4chan_x.user.js
	script.coffee
post.hasPdf

Conflicts:

	4chan_x.user.js
	script.coffee
ImageExpand.expand: return if pdf

Conflicts:

	4chan_x.user.js
	script.coffee
tweak

Conflicts:

	4chan_x.user.js
	script.coffee