winbuild: Added support for VC15

winbuild/BUILD.WINDOWS.txt

@@ -65,7 +65,7 @@ a directory named using the options given to the nmake call.
 nmake /f Makefile.vc mode=<static or dll> <options>
 
 where <options> is one or many of:
-  VC=<6,7,8,9,10,11,12,14>     - VC versions
+  VC=<6,7,8,9,10,11,12,14,15>  - VC versions
   WITH_DEVEL=<path>            - Paths for the development files (SSL, zlib, etc.)
                                  Defaults to sibbling directory deps: ../deps
                                  Libraries can be fetched at http://windows.php.net/downloads/php-sdk/deps/

winbuild/Makefile.vc

@@ -15,7 +15,7 @@ CFGSET=true
 
 !MESSAGE Usage: nmake /f Makefile.vc mode=<static or dll> <options>
 !MESSAGE where <options> is one or many of:
-!MESSAGE   VC=<6,7,8,9,10,11,12,14>     - VC versions
+!MESSAGE   VC=<6,7,8,9,10,11,12,14,15>  - VC versions
 !MESSAGE   WITH_DEVEL=<path>            - Paths for the development files (SSL, zlib, etc.)
 !MESSAGE                                  Defaults to sibbling directory deps: ../deps
 !MESSAGE                                  Libraries can be fetched at http://pecl2.php.net/downloads/php-windows-builds/

winbuild/MakefileBuild.vc

@@ -5,7 +5,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1999 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
+# Copyright (C) 1999 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
 #
 # This software is licensed as described in the file COPYING, which
 # you should have received as part of this distribution. The terms
@@ -22,7 +22,7 @@
 
 ###########################################################################
 #
-# Makefile for building libcurl with MSVC 6, 7, 8, 9, 10, 11, 12 and 14
+# Makefile for building libcurl with MSVC 6 through to 15
 #
 # Usage: see usage message below
 #        Should be invoked from winbuild directory