Update config.h.win32.in for Newer Windows

Make use of if_indextoname() and if_nametoindex() when building against
Window Vista/Server 2008 or later, as these are provided by the system.

This is not turned on by default as we still want to support XP and
Server 2003-turn this on by changing _WIN32_WINNT to 0x600 or later prior
to compiling GLib.

https://bugzilla.gnome.org/show_bug.cgi?id=730352
gsubprocess: Add a missing va_end() call

Coverity issues: #1214070, #1214069

https://bugzilla.gnome.org/show_bug.cgi?id=730278
gthread: Fix use of a local variable after it went out of scope

This could theoretically cause problems, although in practice we would
have seen them by now (the bug was introduced in 2012).

Coverity issue: #1159486

https://bugzilla.gnome.org/show_bug.cgi?id=730277
gdbus-tool: Remove dead variables

Coverity issues: #1159447, #1159446

https://bugzilla.gnome.org/show_bug.cgi?id=730295
Trivial: fix a guard comment

The conventional comment for the #endif at the bottom of the
header was not matching the #ifdef at the top in glib-private.h.
Fix that.
gobject: unref unused class

If g_type_class_ref() returns a class which is not
a GObjectClass we need to unref it before return in
object_interface_check_properties().

https://bugzilla.gnome.org/show_bug.cgi?id=706983
GDBusError enum: Remove trailing comma.

This is helpful to people using the g++ --pedantic option.
Try to fix mapping-test

The mapping-test is failing under gnome-continuous. I suspect this
is simply due to running many tests in parallel, and mapping-test
being racy. Replace the blind sleep by signals, to avoid the
races.
config.h.win32.in: Define _WIN32_WINNT Conditionally

This is done so that _WIN32_WINNT may be overridden in the project files,
if needed, so that one can access the Vista+ (or so) Windows APIs easier
by using "preprocessor defines" (or so) in the Visual C++ project files.
gio: port annotations from the Vala metadata.

https://bugzilla.gnome.org/show_bug.cgi?id=730493
gtestutils: Error out if /dev/null stdin redirection fails

https://bugzilla.gnome.org/show_bug.cgi?id=730189