Improve changelog generation.

Makefile.am

@@ -26,8 +26,7 @@ upload-doc: doc/html FORCE
 update-changelog: FORCE
 	git --help >/dev/null 2>&1 \
 	  && test -d .git \
-	  && git log --stat | grep -v '^    \(git-svn-id\|$$\)' \
-	      | sed '/^Author:/s/ <.*@.*>//' > ChangeLog
+	  && git log --stat | awk 'function flush() { if (m != "") { print "Commit: " v "\nAuthor: " a m } m=""; v="UNSUBMITTED" } { if ($$1 == "commit") flush(); else if ($$1 == "Author:") { a = $$2 } else if ($$1 == "git-svn-id:") { split($$2,tmp,"@"); v=tmp[2] } else if ($$_ != "    ") { m=m "\n" $$_ } } END { flush() }' > ChangeLog
 
 update-fonts: tools/makefont
 	tools/makefont mono9 "Monospace 9" 96 4 >| $(srcdir)/caca/mono9.data