reload configuration on SIGHUP

use upper bound given by poll it's a waste to loop through all fds. We know the *exact* number of clients that needs attention, so use that information to limit the looping.

drop unnecessary check around close

refactor executor_main now it's symmetrical to listener_main().

refactoring startup logic

revert commit 346f28eeaa205d268d1e63c7ffd86cf041f6d1e6 keep mark_nonblock in utils.c, as otherwise the build for the regress suite will fail (mark_nonblock needs fatal which is in gmid.c, and we can't link gmid.o with the regress suite...)

drop privileges after the fork

fix location example

move mark_nonblock to utils.c

mark various functions as static By marking all those function as static, the compiler is free to do more optimizations. In addition, those functions are not used outside server.c

cgi now follows globbing rules

let LEX and YACC be customizable via args

ignore clangd' compile_flags.txt

print the header in the directory listing

configless: fixing the case of the implicit "." I got bitten by the scope visibility rules. After the end of the block, the path variable is no longer valid, and in fact later load_vhosts fails to open that (because the buffer gets invalidated)