curl_sspi.c: Fixed mingw32-gcc compiler warnings
curl_sspi.c: Fixed length of error code hex output

The hex value was printed as signed 64-bit value on 64-bit systems:
SEC_E_WRONG_PRINCIPAL (0xFFFFFFFF80090322)

It is now correctly printed as the following:
SEC_E_WRONG_PRINCIPAL (0x80090322)

curl_sspi.c: Fallback to security function table version number
Instead of reporting an unknown version, the interface version is used.

curl_sspi.c: Removed SSPI/ version prefix from Curl_sspi_version
curl_schannel: Replaced static buffer sizes with defined names
curl_schannel.c: First brace when declaring functions on column 0
curl_schannel.c: Put the pointer sign directly at variable name
curl_schannel.c: Use structs directly instead of typedef'ed structs
curl_schannel.c: Removed space before opening brace
curl_schannel.c: Fixed lines being longer than 80 chars

Added new function to get SSPI version as string.
Added required library version.lib to makefiles.
Changed curl_schannel.c to use Curl_sspi_version.

Moved type definitions in order to avoid inclusion loop

Moved the error constant switch to curl_sspi.c and added two new helper
functions to curl_sspi.[ch] which either return the constant or a fully
translated message representing the SSPI security status.
Updated socks_sspi.c and curl_schannel.c to use the new functions.

Windows 2000 Professional:  Schannel returns SEC_E_OK instead
of SEC_I_CONTEXT_EXPIRED. If the length of the output buffer
is zero and the first byte of the encrypted packet is 0x15,
the application can safely assume that the message was a
close_notify message and change the return value to
SEC_I_CONTEXT_EXPIRED.

Connection shutdown does not mean that there is no data to read
Correctly handle incomplete message and ask curl to re-read
Fixed buffer for decrypted being to small
Re-structured read condition to be more effective
Removed obsolete verbose messages
Changed memory reduction method to keep a minimum buffer of size 4096

Updated TODO information and added related MSDN articles

Fixed warning: dereferencing pointer does break strict-aliasing rules
by using a union instead of separate pointer variables.
Internal union sockaddr_u could probably be moved to generic header.
Thanks to Paul Howarth for the hint about using unions for this.

Important for winbuild: Separate declaration of sockaddr_u pointer.
The pointer variable *sock cannot be declared and initialized right
after the union declaration. Therefore it has to be a separate statement.

-i without HTTP protocol shall not include headers in the output

Since Curl_pgrsDone() itself calls Curl_pgrsUpdate() which may return an
abort instruction or similar we need to return that info back and
subsequently properly handle return codes from Curl_pgrsDone() where
used.

(Spotted by a Coverity scan)

Fixed USE_IPV6 and USE_IDN not being passed
from Makefile.vc to MakefileBuild.vc
Fixed whitespace and formatting issues
Fixed typo and format in help message

Enhanced the authentication type / mechanism detection in preparation
for the introduction of APOP support.

-J without -O shall not honor C-D filename

Previously it would use a 256 byte buffer and thus cut off very long
subject names. The limit is now upped to the receive buffer size, 16K.

Bug: http://curl.haxx.se/bug/view.cgi?id=3533045
Reported by: Anthony G. Basile

Bug: https://bugzilla.redhat.com/788526
Reported by: Enrico Scholz

forward declare the Configurable struct

Commit eeeba149 removed them and thus broke my Linux build

when calloc fails, return error! (Detected by Fortify)

Reported by: Robert B. Harris

Additionally, make hash checking ability mandatory in order to allow metalink
support in curl.

A command line option could be introduced to skip hash checking at runtime,
but the ability to check hashes should always be built-in when providing
metalink support.

Previously it could easily wrongly get repeated