Fix remove_double_dots_and_double_slashes removing all the dots leading http server to serve wrong URI

If the uri is something like '/js/...jquery.js', remove_double_dots_and_double_slashes will remove the 3 dots and the http server will serves the /js/jquery.js file.
remove_double_dots_and_double_slashes should check if a dot or double dots is followed by a slash (or backslash) and only remove this to avoid disclosure attack.

Enable building of example/Makefile on Win32

Compile fix

fix compiler warnings for 64 bit compilation

web_server_ssl

websocket_ssl_proxy sample for polarsll

OS/2 patches by KO Myung-Hun

Allow for compilation in Visual Studio with NS_ENABLE_IPV6.

Upstream patch from MAME project

Replace obsolete gethostbyname by getaddrinfo

Fix for MINGW builds

Only define _XOPEN_SOURCE on Linux.

Fixes the build on NetBSD.

The comment says it's only needed on Linux, and AFAIK Linux
is the only operating system that only adds symbols when it's defined;
others, like NetBSD or Solaris, also hide symbols.

Signed-off-by: Thomas Klausner <wiz@NetBSD.org>