use recv()/send() instead of read()/write() with sockets

sendf is now only Curl_sendf
Curl_write() and Curl_read() are here

removed two compiler warnings

Curl_read() and Curl_write() are now used for reading/writing sockets.
Some functions changed prototype due to this change as well.

Get get-ftp-response function is now using Curl_read() for reading from a
socket. Curl_ConnectHTTPProxyTunnel changed prototype.

replaced sendf() calls with Curl_sendf()

Ingo Ralf Blum's cygwin fixes

Robert Weaver's win32 getenv fix, my added comments in some files

Added Robert Weaver as contributor

fixed the comment for 'path'

added comments all over

extended the gname field one byte to avoid a possible overflow
added lots of explaining comments

Robert Weaver's fix

generated by autoheader

ipv6 adjustments

Enabled support for IPv6-style IP-addresses if ENABLE_IPV6 is set. If it isn't,
curl will return an error when such an address is used.

big reorg to make it not exit when it fails, but instead just not do any
globbing, it makes IPv6 support easier and smoother to add.

Added 'ipv6 enabled' for ipv6 compiled versions

Added simple IPv6 recognition support

Bj�rn's progress meter fix, new test cases and ftpserver.pl patch

Bj�rn Stenberg's patch for making the progress meter betterlooking

the custom reply engine was not inited properly

test case 121

Added test case 120, ftp with '-Q -'

Removed the deprecated -c and -t from the --help output.