Add an ABORT keyword argument to PG-DISCONNECT (from Robert J.
Macomber <pgsql@rojoma.com>), as per CL:CLOSE.

  "I've run into a problem with pg-disconnect if something abnormal
   happens to the database connection -- if the database goes away for a
   restart while pg has a connection open, for example.  When this
   happens, pg-disconnect fails, and the socket file descriptor is left
   open (presumably for a finalizer to clean up), also raising a new
   error from the unwind-protect in with-pg-connection.  To guard against
   the possibility, I've added an :abort parameter to pg-disconnect, like
   cl:close has, and made with-pg-connection call it with :abort t if the
   body exits abnormally, in the same way that with-open-file operates.
   When :abort is true, the modified pg-disconnect closes the database
   connection ungracefully, including making the close call abort
   (otherwise, sbcl at keast tries to flush the stream, raising another
   error if the database isn't there anymore)."

darcs-hash:aad628cf0093846dca55fe4f8fa47b0db89249c2

Allow encoding used for socket communication with the backend to be
specified as a keyword argument to PG-CONNECT, for cases where
rebinding *PG-CLIENT-ENCODING* is inconvenient.

Add a simple test for encoding support.

(From Attila Lendvai <attila.lendvai@gmail.com>)

darcs-hash:9f1f315eb332972142eadea0eff9cb70e5702ece

Make PGLO-READ a generic function, with specializations on the v2 and
v3 protocols. The difference is necessary because the v2 protocol
reads large-object data in text, whereas the v3 protocol changed to
use a binary format.

darcs-hash:6639fd1b9dd10ca051ea03d7e2fbff94c0d917e2

- add md5 authentication (thanks to Brian Mastenbrook). Uses Pierre Mai's
    portable md5.lisp library, that has been added to the project (with extra
    EVAL-WHENness to please OpenMCL and ACL).

    Tested with CMUCL, SBCL, OpenMCL, CLISP, ACL 6.1. ABCL does not compile
    md5.lisp, probably for more EVAL-WHEN reasons. Only tested with PostgreSQL
    version 7.4.

darcs-hash:76581bd5b619a8e593164743a8ff044357c680cb

- improvements to the system-dependent functionality: OpenMCL is
    able to use a local connection to the backend; most
    implementations resignal connection errors as a postgres-error.

  - fixes to the lowlevel code

darcs-hash:81350b160619ff22468166aa3f1928c8f75d9b7e

More factorization of lowlevel functions between v2 and v3 protocols.

darcs-hash:aef9e7feac79e0d6b749d3ff999a62e1f50c4d69

Integrate Peter Van Eynde's v3 protocol support:

   - create PGCON-V2 and PGCON-V3 classes
   - PG-CONNECT attempts to connect using v3 protocol, and falls back
     to v2 protocol for older backends; return a PGCON-V2 or PGCON-V3
     object
   - PG-EXEC and FN and PG-DISCONNECT are generic functions that
     dispatch on the connection type
   - protocol code split into v2-protocol.lisp and v3-protocol.lisp

TBD: cleaning up the notification & error reporting support, and
factorizing more code between the two protocol versions.

Also split code out into multiple files:

   - large-object support
   - metainformation about databases
   - parsing and type coercion support
   - utility functions and macros

darcs-hash:00b6e900f7b48953d959f95e55c26ecee52efb37