On page
http://wiki.splitbrain.org/wiki:config it states:
Hint: The Configfile now includes a file called conf/local.php if it exists.
But this is not true if one thinks of include in a C-way.
I added a (temporary) example to
http://wiki.splitbrain.org/wiki:config#Configuration.
I you want I'll try to make a patch for conf/local.php.dist!