Update and Overhaul the Visual Studio 2010 Projects

Update the project files so that the sources listings in them are kept up
to date.  Also, give the projects an overhaul by consolidating
commonly-used items into property sheets, and moving them to MSVC_Net2010/.
Also, remove the /vd2 compile-time option as it has been found to cause
crashes in the built binaries.

	* MSVC_Net2010/gtkmm-build-defines.props:
	* MSVC_Net2010/gtkmm-version-paths.props: Added property sheet
	  files so that commonly-used items can be consolidated, and can be
	  referred to by the projects, which would simplify future
	  maintenance
	* MSVC_Net2010/gendef.vcxproj:
	* MSVC_Net2010/gendef.vcxproj.filters:
	* MSVC_Net2010/gdkmm/gdkmm.vcxproj:
	* MSVC_Net2010/gdkmm/gdkmm.vcxproj.filters:
	* MSVC_Net2010/gdkmm/gtkmm.vcxproj:
	* MSVC_Net2010/gdkmm/gtkmm.vcxproj.filters: Move to MSVC_Net2010/
	  and clean up using the property sheets.  Remove the /vd2 compile-
	  time option, as it causes more trouble than help.  Adjust the
	  file paths accordingly, and add the sources that have been added
	  during the dev cycle.
	* MSVC_Net2010/demos/gtk-demo/gtk-demo.vcxproj:
	* MSVC_Net2010/demos/gtk-demo/gtk-demo.vcxproj.filters: Move to MSVC_Net2010/
	  and clean up using the property sheets.  Remove the /vd2 compile-
	  time option, as it causes more trouble than help.  Adjust the
	  file paths accordingly, and add the sources that have been added
	  during the dev cycle.  Rename as gtkmm3-demo.
	* MSVC_Net2010/filelist.am:
	* MSVC_Net2010/gtkmm.sln: Update file locations accordingly.