Fixed for Issues 3, 7 & 11

Updated MSBuild targets and NuSpec template (tt),

Fixed Issue 11 - Packaged project incorrectly includes dependencies on
NuGet.PackageNPublish and NuGet.Build.
Fixed Issue 7 - Packaging project includes all dlls in solution when
build via TFS
Fixed Issue 3 - Packaging project includes DLLs from dependent packages