location -> error and locopt -> fastcgi -> error both end up with a optnl that can be reduced to the empty string.

this revamps the syntax in the configuration to better match httpd(8) (and in general be less weird) and to allow per-location fastcgi configurations. the bare `param' is now deprecated, but for compatibility it acts like `fastcgi param' would do now. Same story for `fastcgi <pathÂ>'.

Somehow the compat for __dead is not working properly on macos (cirrus ci) since it complains that parse_debug() does not return a value in all control paths when it uses usage() (marked as __dead) to catch a wrong usage.

various servers are not handling correctly the close notify so for the moment don't turn this into an hard error but just warn. Hopefully, given some time, most servers will be fixed. while here, drop the gotos and just use a break to exit the main loop.