Update the MSVC Project Files

* MSVC_Net2005/gendef/gendef.vcproj:
  MSVC_Net2008/gendef/gendef.vcproj:
  MSVC_Net2010/gendef/gendef.vcxproj:
  MSVC_Net2005/pangomm/pangomm.vcproj:
  MSVC_Net2008/pangomm/pangomm.vcproj:
  MSVC_Net2010/pangomm/pangomm.vcxproj: Clean up the project files by
  purging unneeded entries, macros and whitespace.

  Also improve on the project files by adding to the
  AdditionalIncludeDirectories and AdditionalLibraryDirectories so that
  they can find and use the deps from a local build directory instead
  of using builds in the global include and libs path.  This is useful when
  we are building an unstable release as unstable releases usually require
  the latest unstable releases of their respective deps, which we do not
  usually want to place where they are used globally.