apr-dbd DSO building of DB drivers

[Edward Rudd <ed...@omegaware.com>]

well, took me a little longer than expected.. (annoying libtool).  But I
have the build system doing some backflips to get the DSO's of the DB
drivers built.

Changes:

new subdirectory under dbd of drivers
moved the apr_dbd_pgsql.c from dbd/ into dbd/drivers/
(SVN really needs to add some *extensions* to DIFF to support history of
moves)

Then apply these two patches (one to APR, and the other to APR-util)

http://www.outoforder.cc/downloads/patches/apr-DSO.diff
http://www.outoforder.cc/downloads/patches/apu-DSO.diff

(pan still doesn't support attachments)

Issues to be resolved still:
need to fix up apr_dbd.c to not import the dbd_pgsql symbol statically but
use DSO. (the APR_DSO_BUILD stuff in the previous commit by Nick)

right now the gen-build.py is somewhat DBD specific (I do regexes in the
filename to *figure* the driver name). but it could easily be changed to
be more generic to allow other components of APU to support DSO builds

right now the db drivers are build as libapr_dbd_pgsql.la (with the .so in
the root .libs) may want this in a different directory, but it probably
doesn't matter.

Installation of said DB dso is not yet done.

and naming conventions for the DSOs along with standard install directory
has to be decided.

Let the feedback commence.

Regards,
Edward Rudd