Added most of the Customizing Operations chapter

Forgot one case. On HP-UX 11.00, gethostbyname_r() is properly defined
if -D_REENTRANT is used. Without it, the compiler still accepts the
function prototype but gives a warning about hostent_data going out of
scope. This is because struct hostent_data is not declared. So, we
force an error by trying to set a variable to the struct.

on my test machine! :-)

This was a real bummer!

is given

removed the initial CRLF in the formpost, as they are part of the request
and should be written by the code in http.c!

this work-around is not needed anymore!

  consuming operation that should only be needed to do once. We patched
  libcurl to now only seed on the first connect when unseeded. The seeded
  status is global so it'll now only happen once during a program's life time.

request of its own, it just changes the keyword of a request.

on IPv4-linux machines

a modifier of another type

pointed out this ugliness.

encourage people to use bad functions

little fix seems to correct it. another case where we just returned and
didn't shut off the reading. This bug is introduced in 7.9.3 due to the
new internal "order".

after the headers on a HEAD request. This bug has been added in 7.9.3 and was
mnot present earlier.