allow sieve usage for all mail users
Merge pull request #100 from evgeni/allow_sieve

allow sieve usage for all mail users
massive update of the wheezy templates, but take them with a grain of salt for now, in particular:
- dkim is broken (pending code changes, this affects *everyone* with opendkim i suppose)
- it has received *no* testing (yet)

other noteworthy stuff:
- nginx should be switched to upstream provided fcgi params file, as its essentially the same.
- dovecot should now work with exim4
- for the most part, configs were switched to the commented version if available, that requires some more reading for the admins, but this isn't a problem for you... right? :)

while i don't think any of this will break horribly, like drinking the beer in your fridge or some other nasty stuff, it will still require testing

Signed-off-by: Robert Förster (Dessa) <Dessa@froxlor.org>