(GH-1155) More comprehensive warn on nupkg/nuspec use
(GH-1155) More comprehensive warn on nupkg/nuspec use

When using nupkg or nuspec, ensure the command checking is looking at
whether "pack " is being called instead of just seeing "pack" in
"package-parameters", which doesn't provide the warning it was designed
to provide.

jberezanski/choco,jberezanski/choco,bazzilic/choco,TheBigBear/choco,bazzilic/choco,TheBigBear/choco,jberezanski/choco,TheBigBear/choco