[turba] Patch to add documentation for filter in sources.php

[Chuck Hagenbuch]

Quoting Manilal K M <libregeek at gmail.com>:

>  I have prepared a small patch for documenting the filter settings in
> sources.php.dist. The patch has also an example of retrieving records
> from two different tables using  JOIN. I think this will be helpful
> for those who use turba in future.

Cleaned up and committed - thanks. In the future please attach patches  
as text/plain attachments; much less likely for them to be mangled  
that way.

-chuck

-- 
"we are plastered to the windshield of the bus that is time." - Chris