[Dovecot] Compile Metadata for 2.2.9

[Andreas Schulze]

Denny Fuchs:
> I want to test a Kolab setup, first for private use, later also in  
> the university
same here but horde, not kolab

> I thought, it is plugin, so I tried to find it on the disk ... but  
> nothing found on the Debian (regular Wheezy packages)
I compile the source, no experience with Wheezy packages.

But I just checked I do not explicit enable metadata at compiletime.
Support started in dovecot-2.2.(5-9)? and 2.2.10 did some fixes.
It's simply default and must be configured only.

Andreas