Item12755: socket not closed properly on a reExec

also:

- work around error in FCGI.pm (use of uninitialized value)
- added =quiet= parameter to suppress normal messages
- fixed tainted pid filename
- added system init scripts to start foswiki as a system service
- added documentation how to run foswiki under nginx



git-svn-id: http://svn.foswiki.org/trunk@17290 0b4bb1d4-4e5a-0410-9cc4-b2b747904278