Two new sections in resolve.tex

-- A section about properties of modifications
-- A section with counter examples to too optimistic guesses

Thanks to Angelo Vistoli for discussions
Change a lemma in algebra.tex
References concerning UFD or not 2-dimensional local rings
Locally Noetherian of dimension 0

is a disjoint union of spectra of Artinian local rings
More cases of dim = 0 implies scheme
Small changes in spaces-cohomology.tex