MSVC_Net2008/filelist.am: Fix up Dist'ed Files

	* MSVC_Net2008/filelist.am: Change thread_pool.vcproj to
	  threadpool.vcproj, as that project file has been renamed.
Visual Studio 2008 Projects: Further Cleanups

	* MSVC_Net2008/glibmm-version-paths.vsprops:
	* MSVC_Net2008/glibmm-build-defines.vsprops: Remove unneeded items
	  and move path-related item into glibmm-version-paths.vsprops