Revert "Revert "lighttpd: start Foris and reForis FastCGI backends on demand""

This reverts commit 14abc044.

The issue with reforis starting was that both reforis and lighttpd were creating FCGI socket. Thus lighttpd created socket and send request to it while reForis replaced that socket when it initialized and thus never get the initial request. The removal of socket configuration solves the issue and the patch added here is that fix.

Implements #705 (closed).

I am not reverting Foris configuration in expectation of Foris removal.