Small fixes for improved usage

Rename template
Edit readme file

In the VM configuration:
Enable Host I/O cache
Set NAT forwarding rule for the guest

In the provisioning scripts:
Install guest additions
Change login message
Run the ifup-local script from rc.local
Re-enable the old kernels clean-up and add the -y switch
Set which scripts are for the virtualbox-iso build only

Set hostname in the kickstart