MSVC 2008/2010 Projects: Add "Install" Project

This adds a "install" project for the Visual Studio 2008 and 2010 projects
so that the builds results can be copied to a common directory together
with the depedencies so that they can be integrated and tested together,
and will help to simplify deployment.

* MSVC_Net2008/atkmm-install.vsprops:
* MSVC_Net2008/install.vcproj:
* MSVC_Net2010/atkmm-install.props:
* MSVC_Net2010/install.vcxproj: Add project files and property sheets to
  copy the build results to a common directory in the build root directory.
* MSVC_Net2008/atkmm.sln:
* MSVC_Net2010/atkmm.sln: Include the "install" project in the build.
* MSVC_Net2008/filelist.am: Distribute the newly-added project files and
  property sheets.