Typo in stacks-morphisms.tex

Thanks to Toby Gee
http://stacks.math.columbia.edu/tag/04XQ#comment-461
Clarify proof equivalent notions proper continuous maps

Thanks to Hanno Becker
http://stacks.math.columbia.edu/tag/005M#comment-465
Fix some typos and a mistake

Thanks to Nuno
http://stacks.math.columbia.edu/tag/08KS#comment-466
http://stacks.math.columbia.edu/tag/05QD#comment-467
http://stacks.math.columbia.edu/tag/05QF#comment-468
http://stacks.math.columbia.edu/tag/02MS#comment-469
Typo in algebra.tex

Thanks to JuanPablo
http://stacks.math.columbia.edu/tag/00HL#comment-470
Fix and add a proof

Thanks to Kestutis Cesnavicius
http://stacks.math.columbia.edu/tag/04WQ#comment-472
Typo in morphisms.tex

Thanks to Nuno
http://stacks.math.columbia.edu/tag/08S2#comment-476
Fix typos and improve exposition

Thanks to a
http://stacks.math.columbia.edu/tag/01FY#comment-477
http://stacks.math.columbia.edu/tag/01FZ#comment-478
Fix typos in fields.tex

Thanks to Daniel Gerigk
Typos (Tag 02TD)

Thanks to Olivier Haution