The Stacks project

Topologies: Put in lemmas on how to recognize fpqc coverings

	TODO: Put in the proofs.

Started tags infrastructure

	new file:   scripts/add_tags.py
	modified:   scripts/functions.py
	new file:   tags/initial_tags
	new file:   tags/tags

More neurotic changes

	modified:   algebra.tex
	modified:   algebraic.tex
	modified:   categories.tex
	modified:   scripts/parse.py
	modified:   sheaves.tex
	modified:   simplicial.tex
	modified:   spaces.tex
	modified:   topologies.tex
	modified:   topology.tex

Start to begin more serious stuff on topologies and algebraic spaces

	modified:   Makefile
	modified:   chapters.tex
	modified:   etale.tex
	new file:   fpqc-descent.tex
	modified:   preamble.tex
	modified:   spaces.tex
	modified:   stacks-git.htm
	new file:   topologies.tex

Added stuff on fppf. fpqc, etale sites

	modified:   categories.tex
	modified:   etale.tex
	modified:   sets.tex
	modified:   sites.tex