Update to 2.5.4:

What's new in psycopg 2.5.4
^^^^^^^^^^^^^^^^^^^^^^^^^^^

- Added :sql:`jsonb` support for PostgreSQL 9.4 (:ticket:`#226`).
- Fixed segfault if COPY statements are passed to `~cursor.execute()` instead
  of using the proper methods (:ticket:`#219`).
- Force conversion of pool arguments to integer to avoid potentially unbounded
  pools (:ticket:`#220`).
- Cursors :sql:`WITH HOLD` don't begin a new transaction upon move/fetch/close
  (:ticket:`#228`).
- Cursors :sql:`WITH HOLD` can be used in autocommit (:ticket:`#229`).
- `~cursor.callproc()` doesn't silently ignore an argument without a length.
- Fixed memory leak with large objects (:ticket:`#256`).
- Make sure the internal ``_psycopg.so`` module can be imported stand-alone (to
  allow modules juggling such as the one described in :ticket:`#201`).


(wiz)