Fail with CURLE_NOT_BUILT_IN when none of requested auth methods is supported.

Reject CURLAUTH_ONLY bit when given alone or with CURLAUTH_NONE.

Data type of internal vars holding CURLAUTH_* bitmasks changed from 'long' to
'unsigned long' for proper handling and operating.

Info: http://curl.haxx.se/mail/lib-2012-04/0170.html

Explicit conversion to 'long' of curl_easy_setopt() third argument for options
CURLOPT_HTTPAUTH and CURLOPT_PROXYAUTH given that this is how its bitmasks are
docummented to be used.

By comparing if a different "progress point" is reached or not since the
previous update, the progress function callback for this now avoids many
superfluous screen updates. This has the nice side-effect that it fixes
a problem that causes a second progress meter line.

The second line output happened because when we use the -# progress
meter, we force a newline output after the transfer in the main loop in
curl, but when libcurl calls the progress callback from
curl_easy_cleanup() it would then output the progress display
again. Possibly the naive newline output is wrong but this optimization
was suitable anyway...

Reported by: Daniel Theron
Bug: http://curl.haxx.se/bug/view.cgi?id=3517418

When building a Windows target with gcc 4.5 or newer and strict compiler
warnings enabled use -Wno-pedantic-ms-format in addition to other flags.

Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=745224

Include stdbool.h only when it is available and configure is capable of
detecting a proper 'bool' data type when the header is included.

Compilation fix for old or unpatched versions of XL C compiler.

Report: http://curl.haxx.se/mail/archive-2012-04/0022.html

Usage in other code paths already protected and requiring even newer versions.

This protects from attribute names being defined by third party's code.

Improvement: http://curl.haxx.se/mail/lib-2012-04/0127.html

NSS_InitContext() was introduced in NSS 3.12.5 and helps to prevent
collisions on NSS initialization/shutdown with other libraries.

Bug: https://bugzilla.redhat.com/738456

This bumps the minimal supported version of NSS to 3.12.x.

Allow repeatable file name length reduction on file names with underscore or
dash characters. This is done in order to better support libcurl's existing
source file names and allow OS/400 package to build out of the box again.

configure script now provides conditional definitions for Makefile.am
that result in CURL_HIDDEN_SYMBOLS being defined by resulting makefiles
when appropriate.

Additionally, configure script option for symbol hiding control is now
named --enable-symbol-hiding --disable-symbol-hiding. While still valid,
old option name --enable-hidden-symbols --disable-hidden-symbols will
be deprecated in some future release.

Undefining CURL_HIDDEN_SYMBOLS in source files isn't the proper fix.

Undefine CURL_HIDDEN_SYMBOLS libcurl private preprocessor macro that might
leak from lib/setup.h into source files where this should not be defined.

Undefine CURL_HIDDEN_SYMBOLS libcurl private preprocessor macro that might
leak from lib/setup.h into source files where this should not be defined.

lib/config-win32.h no longer copied to src/config-win32.h

BUILDING_LIBCURL and CURL_STATICLIB are no longer defined in curl_config.h,
configure will generate appropriate conditionals so that mentioned symbols
get defined and used in Makefiles at compilation time

amigaos.[ch] now integrates nicely with any libcurl build