Reorganize makefile snippets

changes.make

-.FORCE:
-
-changes.tex: Makefile .FORCE
-	astron-texmf/bin/gen_change_record.py > changes.tex

example/Makefile

@@ -8,4 +8,4 @@ $(DOCNAME).pdf: $(DOCNAME).tex meta.tex
 	xelatex $(DOCNAME)
 	xelatex $(DOCNAME)
 
-include ../vcs-meta.make
+include ../make/vcs-meta.make

make/changes.make

+.FORCE:
+
+changes.tex: Makefile .FORCE
+	rm -f $@
+	printf "%s\n" "% GENERATED FILE -- do not edit" >>$@
+	astron-texmf/bin/gen_change_record.py >>$@

vcs-meta.make → make/vcs-meta.make

@@ -7,7 +7,7 @@ GITLASTYEAR := $(shell git log -1 --date=short --pretty=%ad | cut -d- -f1)
 
 meta.tex: Makefile .FORCE
 	rm -f $@
-	printf "%s\n" "% GENERATED FILE -- edit this in the Makefile" >>$@
+	printf "%s\n" "% GENERATED FILE -- do not edit" >>$@
 	printf "%s\n" "\newcommand{\vcsRevision}{$(GITVERSION)}" >>$@
 	printf "%s\n" "\newcommand{\vcsDate}{$(GITDATE)}" >>$@
 	printf "%s\n" "\newcommand{\vcsFirstYear}{$(GITFIRSTYEAR)}" >>$@