Put in some migration guides. Should have had these for each release.

migration/6.0_to_6.1

+This migration requires a complete dump of the 6.0 database and a
+restore of the database in 6.1.
+
+Those migrating from earlier 1.* releases should first upgrade to 1.09
+because the COPY output format was improved from the 1.02 release.

migration/6.1_to_6.1.1

+This is a minor bug-fix release. A dump/reload is not required from v6.2,
+but is required from any release prior to v6.2.
+
+In upgrading from v6.2, if you choose to dump/reload you will find that
+avg(money) is now calculated correctly. All other bug fixes take effect
+upon updating the executables.

migration/6.1_to_6.2

+This migration requires a complete dump of the 6.1 database and a
+restore of the database in 6.2.
+
+Note that the pg_dump and pg_dumpall utility from 6.2 should be used
+to dump the 6.1 database.
+
+Those migrating from earlier 1.* releases should first upgrade to 1.09
+because the COPY output format was improved from the 1.02 release.

migration/6.2_to_6.2.1

+This is a minor bug-fix release. A dump/reload is not required from v6.2,
+but is required from any release prior to v6.2.
+
+In upgrading from v6.2, if you choose to dump/reload you will find that
+avg(money) is now calculated correctly. All other bug fixes take effect
+upon updating the executables.