File Release Notes and Changelog

     * Add 'E' command to show query plan of a running query.
     * Add parameters to specify database connection information.
     * Add 'L' command to show locks held by a process.
     * Add 'Q' command to show current query of a process.
     * Rename 'top' to 'ptop'.
     * Add support for Linux.
     * Configure support for PostgreSQL libpq client libraries.
     * Remove old_modules directory.
     * Update RES calculation for Linux 2.6.x.