update todo

          recently, and not try for a while if so

        o check tor version as soon as you get the recommended-versions

          string, regardless of whether parsing the directory succeeded.

NICK    - Check directory signature based on signer ID, not on who

NICK    o Check directory signature based on signer ID, not on who

          we got it from

ARMA	- Increase all the scalability constants

ARMA    o Increase all the scalability constants

For scalability:

        - Slightly smarter bandwidth management: use link capacity