Release v0.35.5.

Fixes:
- 1a458a9 server: handle duplicate request IDs within a single batch (#77)
- b6901af Front-load handling of callback responses from the client. (#79)

Cleanup:
- 9cb4b74 Document method origin in ParseQuery.
- 8b046b1 Add more goroutine leak checks.
- f2aaf13 Use code strings consistently.