Log Message:
-----------
Trim down release section headings (no need for Changes).
Re-order some items as migration changes.
Modified Files:
--------------
pgsql/doc/src/sgml:
release.sgml (r1.548 -> r1.549)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release.sgml?r1=1.548&r2=1.549)