already been transfered no longer returns error but instead is OK. The
reasoning behind this is of course that no extra actions need to be taken
and it is as if a transfer had been successfully performed.

main handle struct to work with persistant connections

from urldata to connectdata, quite correctly.

be used for the close policy decision

store it.

since they were out-of-date and not correct anymore.

moved around some struct fields

intermixed HTTP and FTP persistant connections also work!

I merely stuffed them here before I decide where they belong and if they
are to remain at all

for what HTTP request that is being used. The old bit-style fields are still
in there as well.

added lots of explaining comments

since it has to survive http struct deletion

requests