Fix a null ref exception when opening .nuspec file that doesn't specify an assembly reference. Work items: 47
Fix a null ref exception when opening .nuspec file that doesn't specify an assembly reference. Work items: 47

dsplaisted/NuGetPackageExplorer,BreeeZe/NuGetPackageExplorer,NuGetPackageExplorer/NuGetPackageExplorer,campersau/NuGetPackageExplorer,NuGetPackageExplorer/NuGetPackageExplorer