Adjust FreeBSD version check to follow FreeBSD Porter's Handbook

http://www.freebsd.org/doc/en/books/porters-handbook/porting-versions.html

  headers work correctly even on FreeBSD systems before v8.

curl.h, adjusting auto-makefiles include path, to enhance portability to
OS's without an orthogonal directory tree structure such as OS/400.

  the define CURL_MAX_HTTP_HEADER which is even exposed in the public header
  file to allow for users to fairly easy rebuild libcurl with a modified
  limit. The rationale for a fixed limit is that libcurl is realloc()ing a
  buffer to be able to put a full header into it, so that it can call the
  header callback with the entire header, but that also risk getting it into
  trouble if a server by mistake or willingly sends a header that is more or
  less without an end. The limit is set to 100K.

test script

it breaks almost all autobuilds.

Fix OS400 makefile for tests to use the new Makefile.inc in libtest
Update the OS400 wrappers and RPG binding according to the current CVS source state

  They introduce known_host support for SSH keys to libcurl. See docs for
  details.

BUG: curl did not build with cmake with VS 2005 for two reasons, ws2tcpip.h requires winsock2.h to be included before it with that compiler, and wldap32 is not available with the default install of the compiler, so disable ldap support if that is not found

With the curl memory tracking feature decoupled from the debug build feature,
CURLDEBUG and DEBUGBUILD preprocessor symbol definitions are used as follows:

CURLDEBUG used for curl debug memory tracking specific code (--enable-curldebug)

DEBUGBUILD used for debug enabled specific code (--enable-debug)

So, until fixed this will remain FIXME.

  Chen pointed out how curl couldn't upload with resume when reading from a
  pipe.

  This ended up with the introduction of a new return code for the
  CURLOPT_SEEKFUNCTION callback that basically says that the seek failed but
  that libcurl may try to resolve the situation anyway. In our case this means
  libcurl will attempt to instead read that much data from the stream instead
  of seeking and that way curl can now upload with resume when data is read
  from a stream!