PATCH: Much improved FTP support!!

Hi,

This is version 2 of my FTP patch. It is a much improved version of the
patch I posted some days ago. It applies to the same version of the source
than my previous patch, so to apply this one you might have to reverse the
one I posted previously.

This version has:

1.) Proper support for persistant connections
2.) Does not use the unnecessary (because of 1.) REIN command anymore
3.) Fixes a bug that might cause the FTP code to hang libwww for small
    transfers and fast Machines on slow Networks (i.e. the internet)
    [The code could not cope with multiple return codes in one read from
    the control connection]
4.) Fixes a "racing condition" (not quite) between the events of the
    control and the data connection that causes the to-be persistant 
    connection to be closed. Fixed by using the priorities of the
    event loop mechanism.

I'm very happy with this version, and I cannot see any obvious bugs. I
was able to transfer the same small file via the same persistant
connection 650 times.... testing continues.

peter  

-- 
Peter Stamfest                    UNIX, Networking & Computing Consultant