Move 8.4 files to their own directory.

diff --git a/ansarticle-preprint.cls b/8.4/ansarticle-preprint.cls
similarity index 100%
rename from ansarticle-preprint.cls
rename to 8.4/ansarticle-preprint.cls

diff --git a/anslistings.sty b/8.4/anslistings.sty
similarity index 100%
rename from anslistings.sty
rename to 8.4/anslistings.sty

diff --git a/deal84.bib b/8.4/deal84.bib
similarity index 100%
rename from deal84.bib
rename to 8.4/deal84.bib

diff --git a/deal84.tex b/8.4/deal84.tex
similarity index 100%
rename from deal84.tex
rename to 8.4/deal84.tex