Adding open-vm-tools to core group

[Ravindra Kumar]

> I think it's probably really better in the "@standard" package group, which
> is one step up from core. People who want a minimal installation but know
> they'll be in vmware can add it directly.

Thanks Matthew. I think @standard package should work. Could you please
help me with the process? I don't really see anything mentioned about it
in this document, https://fedoraproject.org/wiki/How_to_use_and_edit_comps.xml_for_package_groups.

Thanks,
Ravindra