Rename add_nic_to_vm to add_hostonly_adapter_to_vm
Changing NIC type to 1Gbps
Set video memory to 16MB
Making storage controllers with enabled hostiocache option
vm.vbs: adding function add_nat_to_vm
product.vbs: adding function print_no_internet_connectivity_banner
product.vbs: fixing function print_no_internet_connectivity_banner