added some text about PASV and PORT and stuff

 getting lost.

FTP Peculiarities We Need

 FTP transfers use a second TCP/IP connection for the data transfer. This is

 usually a fact you can forget and ignore but at times this fact will come

 back to haunt you. libcurl offers several different ways to custom how the

 second connection is being made.

 libcurl can either connect to the server a second time or tell the server to

 connect back to it. The first option is the default and it is also what works

 best for all the people behind firewals, NATs or ip-masquarading setups.

 libcurl then tells the server to open up a new port and wait for a second

 connection. This is by default attempted with EPSV first, and if that doesn't

 work it tries PASV instead. (EPSV is an extension to the original FTP spec

 and does not exist nor work on all FTP servers.)

 You can prevent libcurl from first trying the EPSV command by setting

 CURLOPT_FTP_USE_EPSV to FALSE.

 In some cases, you will perfer to have the server connect back to you for the

 second connection. This might be when the server is perhaps behind a firewall

 or something and only allows connections on a single port. libcurl then

 informs the remote server which IP address and port number to connect to.

 This is made with the CURLOPT_FTPPORT option. If you set it to "-", libcurl

 will use your system's "default IP address". If you want to use a particular

 IP, you can set the full IP address, a host name to resolve to an IP address

 or even a local network interface name that libcurl will get the IP address

 from.

Headers Equal Fun

 Some protocols provide "headers", meta-data separated from the normal