File Release Notes and Changelog

- works now with PG 8.2
- RPM packages available at:
http://developer.postgresql.org/~devrim/rpms/other/postgresql-table_log/
- Debian packages available soon in Sid
- some smaller code cleanups
- use PGXS build environment
- cleaned up the documentation

- removed the second Makefile, PGXS makes a fine job here
- removed some warnings