fix(fuse): wait for a create on the wire that holds the name (B154); a write whose answer was lost is not a conflict (B155)

B154 is a regression from the B153 fix: after a failure on a held name the
op woke the ops waiting for it, but the database cannot see a create on the
wire, so the op was due again at once and spent its waits in milliseconds.
No wake while another create on the wire holds the name.

B155: a revision upload that reached Drive but lost its answer left the
file at a revision this daemon never heard of, and the retry kept the write
as a conflict copy of itself. A complete write whose bytes the remote holds,
by size and SHA-1, is sent again instead.

The fake Drive gains hold_reply_to_next_create and
lose_reply_to_next_revision for the two new sim tests.

docs/CHANGELOG.md

@@ -33,6 +33,10 @@ folder by local id too.
   for this release.
 
 ### Fixed
+- **A file made under the name of a file whose upload is still going out keeps its name.** It
+  no longer lands as a conflict copy, and the mount no longer shows that copy's name (B154).
+- **A change to a file no longer lands as a conflict copy of itself when the link loses Drive's
+  answer to its upload** (B155).
 - **A file renamed just as its upload finished keeps its new name.** The mount no longer showed
   the old name, and a second rename no longer failed with "No such file or directory" (B152).
 - **A change that waits for a name to be freed no longer waits seconds after it is.** A rename or