clean up the headers better

sooner

Ultrix by Damien Adant <dams@usa.net>.

I didn't get that far! ;-)
I also made curl *not* prevent the progress meter even if the output is a tty
when your uploading (it is still done when downloading though). A HTTP POST
is in that sense seen as an upload. It seemed so confusing that ftp upload
doesn't display a progress meter by default.

  deal with any-length lines, removing the previous limit of 4K.

sorted out the -y and -Y confusion in the help texts