add initial CMake and Visual Studio build support

This moves the compatibility include files from include to
include/compat so we can use the awful MS C compiler
<../include/> trick to emulate the GNU #include_next extension.

This also removes a few old compat files we do not need anymore.

patches/arc4random.c.patch

@@ -0,0 +1,15 @@
+--- crypto/compat/arc4random.c.orig	2015-07-20 07:41:17.000000000 -0600
++++ crypto/compat/arc4random.c	2015-07-20 07:41:58.000000000 -0600
+@@ -36,8 +36,11 @@
+ #define KEYSTREAM_ONLY
+ #include "chacha_private.h"
+ 
++#ifndef min
+ #define min(a, b) ((a) < (b) ? (a) : (b))
+-#ifdef __GNUC__
++#endif
++
++#if defined(__GNUC__) || defined(_MSC_VER)
+ #define inline __inline
+ #else				/* !__GNUC__ */
+ #define inline

patches/openssl.c.patch

@@ -1,10 +1,11 @@
---- apps/openssl.c.orig	2015-06-05 03:42:12.956112944 -0500
-+++ apps/openssl.c	2015-06-05 03:41:54.215381908 -0500
-@@ -130,6 +130,18 @@
+--- apps/openssl.c.orig	2015-07-20 02:01:42.000000000 -0600
++++ apps/openssl.c	2015-07-20 02:02:00.000000000 -0600
+@@ -130,6 +130,19 @@
  #include <openssl/engine.h>
  #endif
- 
+
 +#ifdef _WIN32
++#include <io.h>
 +#include <fcntl.h>
 +static void set_stdio_binary(void)
 +{
@@ -18,12 +19,22 @@
 +
  #include "progs.h"
  #include "s_apps.h"
- 
-@@ -216,6 +228,7 @@
+
+@@ -204,7 +216,9 @@
+ static void
+ openssl_startup(void)
+ {
++#ifndef _WIN32
+ 	signal(SIGPIPE, SIG_IGN);
++#endif
+
+ 	CRYPTO_malloc_init();
+ 	OpenSSL_add_all_algorithms();
+@@ -216,6 +230,7 @@
  #endif
- 
+
  	setup_ui_method();
 +	set_stdio_binary();
  }
- 
+
  static void

patches/opensslconf.h.patch

@@ -0,0 +1,13 @@
+--- include/openssl/opensslconf.h.orig	2015-07-19 23:21:47.000000000 -0600
++++ include/openssl/opensslconf.h	2015-07-19 23:21:17.000000000 -0600
+@@ -1,6 +1,10 @@
+ #include <openssl/opensslfeatures.h>
+ /* crypto/opensslconf.h.in */
+
++#if defined(_MSC_VER) && !defined(__attribute__)
++#define __attribute__(a)
++#endif
++
+ /* Generate 80386 code? */
+ #undef I386_ONLY
+

patches/ossl_typ.h.patch

@@ -1,15 +1,17 @@
 --- include/openssl/ossl_typ.h.orig	2015-07-06 13:21:18.788571423 -0700
 +++ include/openssl/ossl_typ.h	2015-07-06 13:24:14.906468003 -0700
-@@ -100,6 +100,20 @@
+@@ -100,6 +100,22 @@
  typedef struct ASN1_ITEM_st ASN1_ITEM;
  typedef struct asn1_pctx_st ASN1_PCTX;
 
 +#if defined(_WIN32) && defined(__WINCRYPT_H__)
++#ifndef LIBRESSL_INTERNAL
 +#ifdef _MSC_VER
 +#pragma message("Warning, overriding WinCrypt defines")
 +#else
 +#warning overriding WinCrypt defines
 +#endif
++#endif
 +#undef X509_NAME
 +#undef X509_CERT_PAIR
 +#undef X509_EXTENSIONS

patches/pkcs7.h.patch

@@ -1,15 +1,17 @@
 --- include/openssl/pkcs7.h.orig	2015-07-06 13:26:27.369203527 -0700
 +++ include/openssl/pkcs7.h	2015-07-06 13:27:37.637051967 -0700
-@@ -69,6 +69,16 @@
+@@ -69,6 +69,18 @@
  extern "C" {
  #endif
 
 +#if defined(_WIN32) && defined(__WINCRYPT_H__)
++#ifndef LIBRESSL_INTERNAL
 +#ifdef _MSC_VER
 +#pragma message("Warning, overriding WinCrypt defines")
 +#else
 +#warning overriding WinCrypt defines
 +#endif
++#endif
 +#undef PKCS7_ISSUER_AND_SERIAL
 +#undef PKCS7_SIGNER_INFO
 +#endif

patches/x509.h.patch

@@ -1,15 +1,17 @@
 --- include/openssl/x509.h.orig	2015-07-06 13:15:15.059306046 -0700
 +++ include/openssl/x509.h	2015-07-06 13:16:10.506118278 -0700
-@@ -112,6 +112,17 @@
+@@ -112,6 +112,19 @@
  extern "C" {
  #endif
 
-+#if defined(_WIN32) && defined(__WINCRYPT_H__)
++#if defined(_WIN32)
++#ifndef LIBRESSL_INTERNAL
 +#ifdef _MSC_VER
 +#pragma message("Warning, overriding WinCrypt defines")
 +#else
 +#warning overriding WinCrypt defines
 +#endif
++#endif
 +#undef X509_NAME
 +#undef X509_CERT_PAIR
 +#undef X509_EXTENSIONS