The Stacks project

Cosmetic change

	Given a named theorem, such as Chevalley's theorem, we now code
	this as

	\begin{theorem}[Chevalley's theorem]
	\label{theorem-chevalley}

	and not as

	\begin{theorem}
	\label{theorem-chevalley}
	(Chevalley's Theorem.)

Terminology:
	"group space" ---> "group algebraic space"
	"groupoid space" ---> "groupoid in algebraic spaces"

	It seems more natural this way to at least three people, and in
	any case it prevents the possible confusion that may arise from
	the fact that in some places in the literature the word "space"
	sometimes refers to any sheaf on schemes in the fppf topology.

Tags: added new tags

Groupoid spaces: Towards stackify

	What we have to do now is stackify a groupoid space. Hence we
	have to rewrite (the easy parts of) the chapter on groupoid
	spaces, and then add some material on stackifying groupoid
	spaces. This is all preliminary before starting to discuss
	presentations of algebraic stacks.