MSVC Introspection Builds: Clean up a bit

Since gobject-introsection-1.40.0 we are passing in the .lib file(s) to
deduce the DLL(s) that the introspection files should look for, instead of
just passing in the DLL file(s), we no longer need to make a copy of the
main .lib file to match the <namespace-name>-<namespace-version> convention
for use during the linking stage of the introspection build.  Remove that
from the introspection builds as a result.
Build: Provide Simple Support for MSVC 2012/2013

As the Visual Studio 2012/2013 are only slightly different from the Visual
Studio 2010 projects, we can provide support for them by using scripts to
copy the Visual Studio 2010 projects, and update the specific parts as
necessary.

Thus, there would be little maintenance overhead for these as only the 2010
projects need to be kept up-to-date as a result.  This might change when we
do get the stack working with WinRT/Metro, but that's going to be another
totally different issue.
Merge branch 'master' of git://git.gnome.org/gdk-pixbuf