Make redbean StoreAsset() work better

- Better UBSAN error messages
- POSIX Advisory Locks polyfills
- Move redbean manual to /.help.txt
- System call memory safety in ASAN mode
- Character classification now does UNICODE

libc/dns/getaddrinfo.c

@@ -26,7 +26,6 @@
 #include "libc/sock/sock.h"
 #include "libc/str/str.h"
 #include "libc/sysv/consts/af.h"
-#include "libc/sysv/consts/ai.h"
 #include "libc/sysv/consts/inaddr.h"
 #include "libc/sysv/errfuns.h"