[sork] fixes/enhancements for vacation ldap driver

[Christian Affolter]

Hi,

After a few fixes I've got the latest (cvs) vacation ldap driver
working. I'm using postfix with gnarwl and the jvd and vacation object
class. Right now it doesn't matters which autoreply system/ldap classes
you're using - it should work for your configuration too, hopefully ;)

Most of my modifications are in the nature of removing hard coded
values/attributes.

All modifications/fixes have been done to lib/Driver.php and
lib/Driver/ldap.php, of course the config/conf.xml was affected too (new
variables, which were previously hard coded).

There was also an issue with character encoding and UTF-8, which should
be fixed by now.

Furthermore I was in the need of adding a special mail alias
(user at example.org -> user at example.org, user at autoreply.exmaple.org).
The above is a requirement for gnarwl (and probably other vacation systems).
That's why I've added two new prototype methods to the ldap driver,
which can be overridden by a special ldap driver, if needed (in my case
gnarwl).
Since ldap mail/vacation setups could be completely different and very
unique to your local infrastructure, I dropped the idea of doing the
alias-thing above generally. It would be too complex to be useful. So
it's easier to extend the ldap driver for your special needs by
overidding only those two methods.

OK folks, enough blah, blah from my side :) If you're interested in my
changes, please advise me how I should publish them (post diff to this
mailing list, bugzilla or whatever?).

regards,
Christian