Update and Overhaul Visual Studio 2010 Projects

Give the Visual Studio 2010 projects, like the Visual Studio 2008 projects
in the previous commits, a much-needed overhaul and cleanup, so to ease
future maintenance, by consolidating commonly-used items into property
sheets.

	* MSVC_Net2010/glibmm-build-defines.props:
	* MSVC_Net2010/glibmm-version-paths.props: New property sheets to
	  consolidate commonly-used items, so that they can be referred to
	  from the projects and changes to them will only have to be done
	  here, which will greatly simplify maintenace of the projects.
	* MSVC_Net2010/glibmm/glibmm.vcxproj:
	* MSVC_Net2010/glibmm/glibmm.vcxproj.filters:
	* MSVC_Net2010/giomm/giomm.vcxproj:
	* MSVC_Net2010/giomm/giomm.vcxproj.filters: Move to MSVC_Net2010/,
	  and clean up by making use of the newly-added property sheets.
	  Update the paths accordingly.  Remove unwanted/unneeded items in
	  them as well.
	* MSVC_Net2010/examples/*/*.vcxproj:
	* MSVC_Net2010/examples/*/*.vcxproj.filters:
	* MSVC_Net2010/tests/*/*.vcxproj
	* MSVC_Net2010/tests/*/*.vcxproj.filters: Move all the projects to
	  MSVC_Net2010/, and adjust the file paths in them accordingly.
	  Clean up by using the property sheets, and remove unwanted/
	  unneeded items.  Remove the example_ and test_ prefixes from the
	  project names, and correct the source file names for the
	  socket-client and socket-server projects
	* MSVC_Net2010/glibmm.sln: Update project names and paths
	  accordingly.
	* MSVC_Net2010/filelist.am: Update file names and paths accordingly