Major update

- Add an IO system to hijack a bit of the terminal.
- Other minor fixes.

src/internal/vase/shard.cc

@@ -200,22 +200,6 @@ Shard *Shard::build(Shard **pieces, uint64_t lo, uint64_t hi) {
   return node;
 }
 
-static bool write_all(int fd, const void *data, size_t len) {
-  const char *p = (const char *)data;
-  while (len > 0) {
-    ssize_t n = write(fd, p, len);
-    if (n > 0) {
-      p += n;
-      len -= (size_t)n;
-      continue;
-    }
-    if (n == -1 && errno == EINTR)
-      continue;
-    return false;
-  }
-  return true;
-}
-
 Shard *Shard::from_command(const char *cmd, OriginalBuffer *o, bool posix_ending) {
   int dest_fd = o->fd;
   if (dest_fd == -1)