mingw: bump the minimum Windows version to Vista

Quite some time ago, a last plea to the XP users out there who want to
see Windows XP support in Git for Windows, asking them to get engaged
and help, vanished into the depths of the universe.

It is time to codify the ascent by the "silent majority" of XP users,
and mark the minimum Windows version required for Git for Windows as
Windows Vista.

This, incidentally, lets us use quite a few nice new APIs.

This also means that we no longer need the inet_pton() and inet_ntop()
emulation, and we no longer need to do the PROC_ADDR dance with the
`CreateSymbolicLinkW()` function, either.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

config.mak.uname

@@ -381,8 +381,6 @@ ifeq ($(uname_S),Windows)
 	NO_PYTHON = YesPlease
 	BLK_SHA1 = YesPlease
 	ETAGS_TARGET = ETAGS
-	NO_INET_PTON = YesPlease
-	NO_INET_NTOP = YesPlease
 	NO_POSIX_GOODIES = UnfortunatelyYes
 	NATIVE_CRLF = YesPlease
 	DEFAULT_HELP_FORMAT = html
@@ -529,8 +527,6 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	NO_REGEX = YesPlease
 	NO_PYTHON = YesPlease
 	ETAGS_TARGET = ETAGS
-	NO_INET_PTON = YesPlease
-	NO_INET_NTOP = YesPlease
 	NO_POSIX_GOODIES = UnfortunatelyYes
 	DEFAULT_HELP_FORMAT = html
 	COMPAT_CFLAGS += -DNOGDI -Icompat -Icompat/win32

git-compat-util.h

@@ -147,7 +147,7 @@
 
 #if defined(WIN32) && !defined(__CYGWIN__) /* Both MinGW and MSVC */
 # if !defined(_WIN32_WINNT)
-#  define _WIN32_WINNT 0x0502
+#  define _WIN32_WINNT 0x0600
 # endif
 #define WIN32_LEAN_AND_MEAN  /* stops windows.h including winsock.h */
 #include <winsock2.h>