Fix bugs and add security features to redbean

- Fix a regression with the previous change that broke redbean
- Add chroot(), resource limit, seccomp, and other stuff to redbean
- Write lots and lots of documentation
- Iron out more system call issues

libc/calls/faccessat-nt.c

@@ -24,5 +24,5 @@
 int sys_faccessat_nt(int dirfd, const char *path, int mode, uint32_t flags) {
   char16_t path16[PATH_MAX];
   if (__mkntpathat(dirfd, path, 0, path16) == -1) return -1;
-  return ntaccesscheck(path16, mode);
+  return __fix_enotdir(ntaccesscheck(path16, mode), path16);
 }