Network Manager

[Andrew J Berkley <berkley@wam.umd.edu>]

I was recently looking through the code of the Network Manager and
realized that there is a lot of old stuff in there (stuff that we phased
out during our internal design stuff -- ie, pre TransferFilter code).
Removing this code and the data members associated with it is relatively
easy.

I think we should extend this Bug Fixing session to a Bug Fixing and Code
Cleanup session (as the less code there is, the less bugs).

There is a major problem with support for blocking calls -- I'm not so
sure we should support them anymore, but the Image stuff uses them (not
successfully of course since the calls are broken).  It is not that hard
to make the FetchURL_b calls work, but I would rather see the Image code
changed.

Andrew