[PATCH] show help even if some RA modules fail to load

I have installed Subversion 1.2.0-1 from Debian GNU/Linux for all
users of this computer. For myself though, I compile versions
from the trunk. When the trunk version tries to load e.g.
libsvn_ra_dav-1.so.0 which I did not build this time, it sees the
one in /usr/lib, fails to initialize it, and just gives up:

kalle@Astalo:~$ svn diff --help
/home/kalle/src/FOREIGN-SVK/svn/subversion/libsvn_subr/version.c:73: (apr_err=200019)
svn: Version mismatch in 'svn_delta': found 1.4.0-dev, expected 1.2.0
/home/kalle/src/FOREIGN-SVK/svn/subversion/libsvn_subr/version.c:73: (apr_err=200019)
svn: Version mismatch in 'svn_subr': found 1.4.0-dev, expected 1.2.0
You have new mail in /var/spool/mail/kalle
kalle@Astalo:~$ svn --version
/home/kalle/src/FOREIGN-SVK/svn/subversion/libsvn_subr/version.c:73: (apr_err=200019)
svn: Version mismatch in 'svn_delta': found 1.4.0-dev, expected 1.2.0
/home/kalle/src/FOREIGN-SVK/svn/subversion/libsvn_subr/version.c:73: (apr_err=200019)
svn: Version mismatch in 'svn_subr': found 1.4.0-dev, expected 1.2.0
kalle@Astalo:~$

I consider this too harsh: even if some RA modules are unusable,
the client should still be able to keep running and use the
others, as if the failing RA module had not existed at all.
With the attached (rather old, but IIRC not posted before) patch,
svn diff --help just works with no complaints, and svn --version
outputs this:

kalle@Astalo:~$ svn --version
svn, version 1.4.0 (dev build)
   compiled Oct 20 2005, 22:10:35

Copyright (C) 2000-2005 CollabNet.
Subversion is open source software, see http://subversion.tigris.org/
This product includes software developed by CollabNet (http://www.Collab.Net/).

The following repository access (RA) modules are available:

* ra_svn : Module for accessing a repository using the svn network protocol.
  - handles 'svn' scheme
* ra_local : Module for accessing a repository on local disk.
  - handles 'file' scheme

The following RA modules exist but cannot be used:

* ra_dav
  - Version mismatch in 'svn_delta': found 1.4.0-dev, expected 1.2.0
  - Version mismatch in 'svn_subr': found 1.4.0-dev, expected 1.2.0